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Clients rate SQL developers
Rating is 4.8 out of 5.
4.8/5
based on 17,705 client reviews
  • $100 hourly
    LinkedIn scraping has become extremely difficult in the last few years – especially at Large Scale. Tools like Phantombuster can scrape hundreds of profiles a day – how can you scale it up to tens of thousands a day for your ambitious projects? You may already try services like proxycurl, but more often than not, their data is outdated (scraped months ago). Using Python, I built the "one of its kind" LinkedIn Scraper for large-volume LinkedIn scraping projects. The system allows me to: ✅ Scrape leads from LinkedIn Sales Navigator searches, including verified emails – Big search? No problem! ✅ Extract LinkedIn people profiles ✅ Extract LinkedIn company profiles ✅ Find decision makers of specific companies on LinkedIn, accurately and quickly ✅ Extract current employees of specific companies on LinkedIn ✅ Extract past employees of specific companies on LinkedIn ✅ Extract all member profiles of specific groups on LinkedIn ✅ Scrape LinkedIn job posts ✅ Find companies on LinkedIn based on a list of web domains or company names What makes my LinkedIn Scraping service different? 💯 Real-time information (up-to-date profiles, not cached data) 💯Large volumes of data — up to thousands and millions of profiles 💯 No need for access to your LinkedIn account or Sales Navigator 💯 Fast, accurate, and customized to your specific criteria People who have used my service once come back whenever they need more data: ⭐️⭐️⭐️⭐️⭐️ "Cung is professional and highly capable. He can do things that many others will say are impossible. Worth every penny. Stop scrolling, and start hiring!" – Mark ⭐️⭐️⭐️⭐️⭐️ "Cung is a master. Excellent skills, fantastic communicator, and an exceptionally talented engineer. If he can't do it, nobody can. Highly recommend!" – Spencer ⭐️⭐️⭐️⭐️⭐️ "Cung is just phenomenal! He is fast, reliable, and accurate and needs only to be pointed to a project and set to go. He thinks on his feet, asks just the right questions, and gets the job done. Just fantastic. Thank you, Cung!" – Peter Barry Ready to get started? Send me a message, and let's talk!
    vsuc_fltilesrefresh_TrophyIcon SQL
    API
    LinkedIn Plugin
    List Building
    Social Media Lead Generation
    LinkedIn
    Data Mining
    Lead Generation
    JavaScript
    Web Crawling
    ETL
    Web Scraping
    Data Scraping
    Python
    Data Extraction
  • $125 hourly
    FHIR certified. Mirth Certified. Jitterbit. 16 years building complex HL7, FHIR API, csv, flat file healthcare interfaces. Standard services include: - affordable price to setup your Athena, Epic and Cerner dev code accounts and build necessary FHIR api calls as an automated Postman collection including the Oauth requirements( this gives your team a jump on healthcare deep integration) or setup Mirth integration engine with pre-built channels. - setup an efficient process for you to convert or map csv, HL7, or database fields to FHIR resources and then deliver to Azure, AWS, GCP, sftp, REST or any application - setup process so you can convert incoming FHIR resources to any data format for your application to ingest. - HL7 v2 integration of all types including: ADT, VXU (vaccine), ORU(imaging or lab), ORM(imaging and lab orders), SIU(scheduling), DFT(charges), MDM(docs), RDE(medications) and many other types of HL7.
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    InterSystems Caché
    Athena Software Penelope
    Epic Systems Medical Software
    Oracle
    FHIR
    Mirth Connect
    Healthcare Interoperability
    Health Level 7
    API Integration
    RESTful API
    Web Service
  • $45 hourly
    My experience includes Powerbuilder (PB) v8 thru PB2019 working with PB Classic, PFC. Please take a moment to view my Portfolio below. It demonstrates window design, Application Design, PB Scripting, and Database skills. The application has been deployed and the EXE has been tested. I have written test plans, Experience with a variety of version control products. Have worked with Upwork and also the Time Tracker. With this background and my extensive working experience, I am able to be productive immediately. A Verified Billing Method is appreciated. Application experience includes working with the 3rd Party PB application, DIAMOND(R) Enterprise System [Health Care]. Industry Experience: Health Insurance, Manufacturing, Mortgage, Compliance Reporting, Employee Surveillance I do not own a version of the Powerbuilder Software. All remote employment has been completed using a remote connection. Ideally, the Client should have all of the Application PBL’s. Projects Available for but not limited to: New Development, Enhancements, The review of an existing application and to document the functionality, Existing Application, determine functionality, Comment Scripts, Assist Business Analysts in finding the functionality for proposed enhancements, Application Migration. Home Office is complete with Audio/Video for meetings and collaboration. Work experience using MS Teams, Webex and Zoom. Thank you for your time. Looking forward to helping you. My goal is to provide excellent work in a timely fashion at a reasonable rate. Not just done, done right. I am a lifelong resident of Pennsylvania, USA.
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    Sybase Programming
    Data Entry
    PowerBuilder
  • $150 hourly
    Hello! Based out of Kansas City, I've worked with well over 100 firms in Consumer goods, technology, Higher Education, and Nonprofits in over ten years in the ExactTarget, Marketing Cloud, Pardot Space. I've worked with lots of well known brands--always assisting with Marketing Cloud implementations. I pride myself in deep expertise, best practices, a friendly nature, and very responsive. I have all of the current Marketing Cloud certifications, all Pardot certifications, as well as Salesforce CRM Admin Certification. I helped to write all of the current Marketing Cloud exams with the Salesforce Cert team. I have opened my own Marketing Cloud consulting firm, Engage Evolution, in Q1 2023. I'd love to chat with you and see how I can help!
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    Salesforce Marketing Cloud
    Pardot Marketing
    HTML
  • $100 hourly
    AI is here and it is creating amazing opportunities for businesses of all sizes and industries. As an experienced data and AI professional, I will help you capitalise on this transformative technology to drive growth and profitability in your business. Whether you need a fully integrated AI application or a quick Proof of Concept to demonstrate its value, I can deliver results that align with your goals. My expertise spans traditional data science, machine learning, cloud solutions, and software engineering, ensuring a seamless integration of AI into your operations. Let’s start discussing how AI can improve your business today.
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    ETL Pipeline
    Data Science
    BigQuery
    Data Mining
    Google Cloud Platform
    Apache Airflow
    Looker
    Data Visualization
    Python
  • $150 hourly
    I combine MBA strategy with advanced Google Tag Manager, Google Analytics, BigQuery/SQL database, and creative problem solving skills to create an Analytics environment that fits your company like a glove. My goal with any engagement is to make sure that the outcome serves to boost your bottom line, either by giving you the tools & insight into where to optimize spend or enhancing your businesses ability to identify and act on opportunities. I will work with you to make your data easy to understand and analysis intuitive.
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    Google Tag Manager
    Analytics
    Google Analytics
    Data Ingestion
    BigQuery
    Data Modeling
    Data Visualization
    Looker
    Domo
    Google Sheets
    Klipfolio
    Tableau
  • $90 hourly
    Senior developer with exposure to a wide variety of environments and a diversity of challenges. Distinction for creative thinking, problem-solving, and resilience in high-pressure situations. Capable of working independently or with a team through the lifecycle of a project. Ability to assist in business analysis and requirements gathering, as well as development, implementation, and support. Approachable, funny, easy-going, and pragmatic. Native English speaker. AREAS OF EXPERTISE • Expert PHP/JavaScript/Rust/Linux/MySQL/HTML/CSS • DevOps AWS/Azure • Cloud application maintenance and management • MySQL database administration • Scaling high traffic websites • Legacy web application development maintenance • Excellent problem-solving skills Need someone experienced and pragmatic to rescue your project? Junior resources spinning wheels and looking for technical guidance? Is Cloud infrastructure getting too complicated? Lucky You, I’m your guy, and I can help!
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    Amazon Web Services
    Linux System Administration
    Unix
    PHP
    JavaScript
    HTML
    Ubuntu
    Linux
    Rust
    Symfony
    CSS
    PostgreSQL
    MySQL
  • $55 hourly
    25+ years experience with MS Access design and development, SQL, Excel, data conversions, integration with Peachtree, Quickbooks and Sage. Developed projects in a range of business environments including Manufacturing, Process Handling/Control, BarCoding, Association Management, Heat Treating, Payroll, Time Card Processing, Web Site Design/Management, Data interface between in-house or web-based systems. Services offered include: - extensive analysis of manual procedures - analysis of industry requirements including ISO conformity and certification - analysis of hardware/software requirements - Design of custom software - Upgrades to existing software - Modifications to existing software - Porting data to or from different formats - Installation and implementation of completed systems - Training of shop floor, office, and management personnel - Customer support via phone, internet, or on site, when location permits. Proficiencies include: - Strong knowledge of MS Access 95 – 2016, Excel, and SQL - Extensive VBA (Visual Basic) Coding, VBA Scripting - Integration of data into Quickbooks, Peachtree, Sage 50 - Data export/import to or from web-based, mySQL or in-house databases. - Graphical representation of data using MS Access or Excel - Automation of manual processes - Dashboard creation, data collection, report generation - ISO conformity and certification. - E-commerce packages – installations, upgrades, customizations - Zen Cart web-design, data conversions, installation of plugins - Creation of end user documentation - Training and seminar classes attended by 1 to 20 plus. - Ease in communication with end users, technicians and management. Please note: the data displayed within portfolios screen-shots is completely fictitious and does not represent any specific person or company. Many forms and reports are proprietary and may not be available here. If you have a specific request, please contact me and I will be happy to assist you.
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    Visual Basic for Applications
    Data Analysis
    Microsoft Access Programming
    Visual Basic
    Microsoft Excel
    Database Administration
    Database Design
    Microsoft Access
  • $150 hourly
    ✅ I'm the highest-rated and highest-earning SQL Server DBA freelancer on Upwork, with more than 100 5-star reviews and overwhelmingly positive feedback. I've solved customer-facing SQL Server bottlenecks and made massive performance improvements for Fortune 500 companies and well-known organizations, including the following to illustrate some of them: ✅ Oracle Cerner (Fortune 500 Company) ✅ CBRE (Fortune 500 Company) ✅ Stanford University ✅ Alltech Inc. (~2.5 Billion Estimated Revenue per Year) ✅ Viega (~150 Million Estimated Revenue per Year) I was featured as the top freelancer in the IT and networking category on Upwork, which has over 116,000 Freelancers in the category (refer to the portfolio section of my profile for details). ⭐ Here's what I can bring to your project ⭐ ✅ Top-notch experience in all versions of SQL Server (2000 - 2022) and cloud platforms ✅ Extensive experience working with large enterprise transactional databases ✅ Expert understanding of data security best practices when working with PII and PHI data ✅ Ability to quickly diagnose SQL performance issues and identify query pain points ✅ Expert ability in designing ETL processes for data warehouses and BI databases ✅ 24/7 ultra-reliable communication: you will always be aware of the project status ✅ Someone who cares about helping you succeed and bringing value to your business ⭐ Why you should choose me over other freelancers ⭐ ✅ Client Reviews: I focus on providing value to all of my clients and earning their TRUST. ✅ Over-Delivering: this is core to my work as a freelancer. My focus is on giving more than what I expect to receive. I take pride in leaving all of my clients saying "WOW" ✅ Responsiveness: being extremely responsive and keeping all lines of communication readily open with my clients. ✅ Resilience: reach out to any of my current or former clients and ask them about my resilience. For any issue that my clients face, I attack them and find a solution. ✅ Kindness: one of the main aspects of my life that I implement in every facet. Treating everyone with respect, understanding all situations with empathy, and genuinely wanting to improve my client's situations. 🏆 Reviews and feedback from high-profile clients 🏆 The client reviews below (also in my work history section) describe the quality of work and value that you can expect from working with me. ⭐⭐⭐⭐⭐ "I've been very impressed working with Josh on a SQL Server DBA project for Stanford University. He took seriously the concerns we had when handling HIPPA-related data. He's professional, detail-minded, and eager to assist other technologists. I definitely will be reaching out to Josh when I need freelance work in the future." - Noah Abrahamson, Stanford University ⭐⭐⭐⭐⭐ "We were in need of a SQL Server DBA to assist us in the upgrade of our CRM and Josh was able to come in and assist us and performed beyond our expectations. He worked on the schedule we needed him to and we are now keeping him on stand-by for future SQL work. If we could give Josh 10 stars we would, he knows what he is doing and genuinely wanted to help us get our migration completed successfully." - Adam Siegel, CBRE ⭐⭐⭐⭐⭐ "Josh is a rockstar. We've used him on a number of projects and thought it was time to close this one and give him the 5-stars that he deserves. He's sliced through everything we've asked of him...replication, high availability, fixing previous DBA sins, optimizing queries and databases, backups, cloud migrations, you name it. Nailed every bit of it." - Anthony Presley, Truno
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    Database Management System
    SQL Server Reporting Services
    SQL Server Integration Services
    Database
    Business Intelligence
    Microsoft Azure SQL Database
    Microsoft SQL Server Programming
    Microsoft SQL Server Administration
    Database Security
    Database Optimization
    Database Administration
    Database Maintenance
    Performance Optimization
    Microsoft SQL Server
  • $60 hourly
    I am TOP RATED, a strong Java and PHP developer from the United States. In the past, I worked for the biggest companies such as Oracle, Accenture, First Data, Barclays Bank, etc. I have 20+ years of experience in web development and I highly specialize in - Java (Java EE, Spring, Spring Boot, Spring Annotations, Spring MVC, Spring Security, JMS, Java Struts, Java Servlets, JSP, Hibernate, MyBatis, REST, ActiveMQ). - PHP (Laravel, WordPress) - Javascript (React, Angular, JQuery, Vue.js) - HTML, CSS, Bootstrap, Tailwind CSS - MySQL, Postgres, Oracle, NOSQL, MongoDB. - AWS, WildFly, Apache Tomcat I have built more than 200 systems and I am comfortable working with both existing and new projects. I helped hundreds of clients in their business and I am here to help you as well!
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    Vue.js
    Web Service
    J2EE
    AngularJS
    HTML
    React
    Laravel
    PHP
    Microservice
    Java Persistence API
    Spring MVC
    Spring Boot
    Spring Framework
    Java
  • $60 hourly
    I am an individual 🧑‍💻 developer with over 15 years 🚀 of experience in the industry. I have worked with both corporations and startups, in traditional and agile environments, in various roles such as Senior PHP Engineer, Tech Leader, and Engineering Manager. I am comfortable working independently or as part of a team and can adapt my approach to optimize resources for projects of any size. If you're looking for a skilled and experienced developer with a strong track record of delivering quality work, please don't hesitate to get in touch ✍. Quick review of my technical skills: ✓ Proficiency in: PHP 7-8, Symfony framework , architecture, backend, Leadership, People management ✓ Good Knowledge of: Symfony 2 to 6, Laravel, Zend Framework, SQL, MySQL, PostgreSQL,Redis, Elasticsearch, Varnish, Rest API, JSON, JavaScript, JQuery, XML, CSS, Git, Less, SAAS , Unit Tests, DDD, Hexagonal architecture ✓ Experienced with: DevOps, Java, Python, Docker, Linux Administration ✓ Additional: Jira, Redmine, ClickUp, Scrum
    vsuc_fltilesrefresh_TrophyIcon SQL
    Angular
    React
    NoSQL Database
    Doctrine ORM
    Architecture
    Ecommerce
    Elasticsearch
    Amazon Web Services
    Twig
    Docker
    Redis
    PHP
    Symfony
    Laravel
  • $250 hourly
    Based in Seattle Washington I provide an expert level of integration skills. I have over 30 years of software development and IT experience working on dozens of back office integration projects involving both SaaS and on-premise CRM, Accounting, ERP, HRIS, HCM and transactional databases. I have worked for the largest software giants (Microsoft) and the smallest tech start-ups. In particular, I have years of experience with Dell Boomi as an API management and integration platform and have used numerous other integration platforms such as Tray.ip, Celigo, APIANT and Zapier. I have a passion for integrating disparate systems, everything from one way pushes to complete, two-way synchronization between systems in real-time or in batch. Just a few of my recent integration and development projects: * Microsoft Dynamics GP to Hubspot * Phorest POS to Shopify and Hubspot * Multiple Apps in Bubble.io * Buildfire Mobile App Development * Netsuite Data Migration/Conversion * White labeled SaaS app store integrations * MLS Real Estate integration w/Salesforce and custom Web Services * DirectScale to Drip customers and orders * Bullhorn ATS to Hubspot, Hubspot forms to Bullhorn two-way integration * (5) ERP to Shiphawk for orders and fulfillment * Dynamics 365 implementation and configuration * JD Edwards to Dynamics 365 Invoices * Salesforce Orders to Netsuite * Salesforce CPQ/Steelbrick quotes to Netsuite SO and Credit Memos * Multiple, Two way Microsoft Team Services and Salesforce Case integration enabling Development and Support to work seamlessly together * Intercom/Salesforce Contact/Account integration * Pipedrive to Mailchimp and Klipfolio * Magento 2.x to Mailchimp Pro integration for dynamic list integration, abandoned cart automation * Two way Salesforce/Netsuite integration enabling Collections activity in Salesforce * Hubspot and Salesforce to FullContact for data enrichment * Shopify purchase certificates via PDF template form generation and emailing * Commercial Concur marketplace app * Bullhorn HR/ATS and Reply.io integration * Netsuite shipping and fulfillment automation * Tipalti to Quickbooks Online * Salesforce Quote to NetSuite Invoicing/Payments * Volusion to Aftership (tracking) * Volusion to Intacct (Invoice/payments) * CRM to MailChimp * Pipedrive to 700 Credit (auto dealership credit reports) * MindBody to Hubspot (Accounts/Contacts) * Amazon FBA to Google Drive * DonorPerfect to Xero * PHP web app leveraging ZoomInfo and Insideview for lead enrichment * Several Hubspot Quickbooks Online integrations * Wordpress/PHP Financial integrations In addition to point-to-point integrations, I also enjoy Business Process Optimization and help you re-engineer and optimize your entire back-office process with modern, connected systems. Always open to hourly consultations for smaller companies looking to leverage my integration, development and leadership experience. Let me show you how I can save you time and money today!
    vsuc_fltilesrefresh_TrophyIcon SQL
    API Development
    Microsoft SQL Server Administration
    .NET Framework
    Dell Boomi
    Shopify
    Microsoft Dynamics Development
    NetSuite Development
    Salesforce CRM
    Apex
    PHP
    C#
    API Integration
  • $40 hourly
    👋 Hello! I'm Santosh Ghimire, a seasoned Python Backend Developer with over a decade of experience, specializing in creating and designing scalable backend systems and crafting efficient automation solutions from the ground up. As a Top Rated Plus freelancer on Upwork, I've had the privilege of working on a wide range of projects. 🌟 What Sets Me Apart: 🔥 A Decade of Expertise: With more than 10 years in the field, I bring a wealth of knowledge and hands-on experience to every project. 🐍 Python Proficiency: Python is my playground. I've mastered this versatile language and can leverage it to create robust, efficient, and scalable backend solutions tailored to your unique needs. 🏗️ System Architecture: Crafting backend systems that scale seamlessly is my forte. I have a knack for designing systems that can grow with your business. 🤖 Automation Wizardry: I specialize in developing automation systems that streamline processes, boost productivity, and save valuable time and resources. 🎓 Academic Excellence: I hold a master's degree in Computer Science from Georgia Tech, a testament to my commitment to continuous learning and staying at the forefront of industry trends. 🔧 What I Can Do for You: Whether you need a powerful backend infrastructure, an automation system to optimize your workflow, or a Python expert to tackle your project, I've got you covered. I thrive on challenging projects and take pride in delivering results that exceed expectations. 🌟 Areas of Expertise: 💻 Scalable Backend Systems: I have a proven track record of designing and implementing highly scalable and efficient backend architectures. Whether it's for web applications, APIs, or complex data processing pipelines, I have the experience to ensure your backend scales seamlessly with your needs. 🤖 Automation Mastery: Automation is at the heart of modern businesses, and I excel in creating automation systems that streamline workflows, reduce manual tasks, and boost productivity. From scripting repetitive processes to building complex automation pipelines, I can help you achieve operational efficiency. 📊 Data Management: Dealing with large datasets? I've got you covered. I can design and implement data storage and retrieval systems that handle big data efficiently, ensuring you can make data-driven decisions with confidence. 🌟 🏗️ Technologies I Master: Python | Django | Flask | SQL | NoSQL | Docker | AWS | RESTful APIs | Celery | Redis | AWS (EC2, S3, Lambda etc) and more. 🌟😃🤝 Client Satisfaction: My commitment to delivering high-quality work and exceeding client expectations has earned me the prestigious Top Rated Plus status on Upwork. I take pride in consistently providing top-notch solutions and outstanding service. 🌟 📈 My Proven Success: My track record on Upwork speaks for itself. I've consistently delivered high-quality work, earned the trust of clients, and built lasting partnerships. Your satisfaction is my top priority. Ready to take your project to the next level? Let's connect and discuss how I can bring your vision to life. Contact me today, and let's get started on your journey to success!
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    Data Science
    Amazon DynamoDB
    Django
    API Development
    System Automation
    Flask
    Amazon Web Services
    Python
    Data Visualization
  • $40 hourly
    • Proven track record in crafting robust software solutions using cutting-edge n-tier architectures. • Demonstrated expertise in object-oriented programming, leveraging the latest methodologies to deliver efficient and scalable code. • Adept at developing and managing databases, ensuring seamless integration and optimal performance. • Possessing formidable analytical, diagnostic, and problem-solving capabilities to tackle complex challenges in software development. • Recognized for a keen optimization mindset, with the ability to quickly grasp and adapt to emerging technologies, showcasing a commitment to continuous learning and innovation. • Exceptional soft skills, as consistently praised by colleagues, including effective communication, teamwork, and a natural ability to collaborate across diverse teams, making a positive impact on project outcomes.
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    JSON
    RESTful API
    Lazarus
    SOAP
    XML
    Scrum
    FHIR
    Firebird
    Microsoft SQL Server
    Service-Oriented Architecture
    Python
    C#
    Back-End Development
    Delphi
  • $100 hourly
    After working for around 20 years in the Software industry, including many projects for public sector clients such as the NHS, National Strategy for Police Information Services and Ambulance & fire services, I have seen the good, the bad and the ugly of large and small scale projects. I've worked with all major technologies and stacks over my career, including Microsoft .NET / .NET Core, Azure, Node / JS etc as well as mobile development with Xamarin / React, and my experience means I'm always able to hit the ground running and add value quickly
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    Microsoft Azure
    Agile Software Development
    Cross Functional Team Leadership
    .NET Core
    Enterprise Architecture
    Azure DevOps
    C#
    .NET Framework
  • $60 hourly
    17+ years of experience working as a Software Engineer/ Architect, building web applications, API services, large scale SaaS services, mobile applications. I have a strong experience in Front-end development, Software Architecture & Design and Principles, Performance tuning, Object Oriented/Functional Design, TDD Relational and NoSQL databases and deployment in the cloud. My skill sets include: Frontend skills: * React.js, Angular, Typescript, Vue, Redux, Redux Saga, Ngrx/store * Firebase * Algolia * Twilio * D3, High Charts * Web Sockets, Socket.IO * Javascript (including ecmascript 8) * Adaptive layouts/frameworks - Google Material, Bootstrap, ant design, skeleton; Backend skills: * Node.js, Javascript, Typescript, Golang, Lua, Python, C++ * express.js, flask, hapi.js, fastify, beego, negroni, nginx, openresty * aws lamda, azure functions, firebase functions * Socket.IO * Mongoose, Sequelize * Amazon AWS development/ Azure App Databases: * Relational: PostgreSQL, Oracle, Mysql * NoSQL: MongoDB, Redis, firestore
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    Rust
    Golang
    API Development
    Reactive Programming
    Front-End Development
    Expo.io
    Database Design
    GraphQL
    React Native
    JavaScript
    TypeScript
    React
    Node.js
  • $14 hourly
    I guarantee to complete all projects accurately and on time. I am motivated, reliable, honest and follow directions well. I am looking to establish myself as one of the top-rated Providers in my field on UpWork. I have 8 years of full time experience in PHP, Laravel, CodeIgniter, Magento, Joomla, Wordpress, Ecommerce websites, woocommerce, shopify, Avada, Divi, Multi-site, Prestoshop, LearnDash, MemberPress, BuddyPress, Member Mouse, S2Member, IDX integration into real estate websites, Genesis Themes, Theme customization, Parent/Child themes, Squarespace, Responsive designs, Plugin development, MySQL, MailChimp, Sendgrid, Visual Composer, Bootstrap, jQuery, AJAX, Javascript, AngularJs, React, VueJS, XAMP, WAMP and worked on more than 100 websites which include Enterprise level application , E-commerce websites , Responsive websites, Mobile device compatible websites. I have extensive experience working on Twillio, Facebook, Instagram, Youtube, Vimeo, Stripe, Google, Eway, Pardot, Moneris, Twitter, DHL, UPS, USPS, FedEx, Safe Save, Payment Spring, Authorize.net, eWay, moneris, ZOHO, Salesforce, Microsoft Dynamics, Coldfusion T4, Concrete5, IDX, Rets, MLS, Cfwheel, Fusebox. I have sound knowledge of domains like Benefits, Ticketting systems and Publishing systems.
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    Website
    API Development
    Web Development
    WordPress Plugin
    HTML
    JavaScript
    PHP
    jQuery
    Bootstrap
    CSS
    HTML5
    WordPress
    MySQL
    AJAX
  • $125 hourly
    ✅ TOP RATED Consultant on UpWork | *100% Client Recommendation Score* My name is Ryan, and I am one of Upwork's highest rated SQL Server DBA (Database Administrator) and Developers. I've worked with numerous companies on projects including database administration, optimization, performance tuning, automation, and SQL programming. If you are having a database issue, you have come to the right place for help. Unlike other database professionals, I am able to effectively communicate to understand your business needs and technical architecture in order to meet your deliverables. I keep my high Job Success Score and Five-Star Feedback rating by accepting only the jobs I know myself to be the best person for. If I'm not completely confident in delivering you the perfect job, I'll let you know and steer you in the right direction. Thank you for reading this far, and I look forward to discussing your project together. Technical Skills: Eleven (11) years of experience in SQL Server versions from 2005-2022, and over 6 years working with Azure and AWS. Certifications: • MCSE: Microsoft SQL Server 2016/2012 Systems Expert Data Platform • MCSA: Microsoft SQL Server 2016/2012 Certified Solutions Associate • MCITP: Microsoft SQL Server 2008 Database Administrator • MCITP: Microsoft SQL Server 2008 Business Intelligence Developer • MCSA: Microsoft SQL Server 2008 Certified Solutions Associate
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    Database Architecture
    Database Maintenance
    SQL Programming
    Microsoft Azure
    Amazon RDS
    Database Management
    Microsoft SQL SSAS
    Microsoft SQL Server Reporting Services
    Transact-SQL
    Database Optimization
    SQL Server Integration Services
    Microsoft Azure SQL Database
    Microsoft SQL Server Administration
    Microsoft SQL Server Programming
    Microsoft SQL Server
  • $68 hourly
    ⭐ Shopify solutions developer ⭐ Shopify Certified Partner/Developer ⭐ Responsive Design & Mobile Web Device Strategies ⭐ Integration of third-party web services ⭐ Theme code customization and configuration ⭐ Strong development background ⭐ SEO optimization and keyword targeting Hello, I am a Shopify certified Full Stack Developer(7 years) with 10+ years ecommerce and digital marketing development experience. My goal is to provide solutions for business challenges on the Shopify platform. My philosophy in providing these solutions is that the business should be able to manage the solution without needing continuous support of a technician. I pride myself on my ability to talk to business operators to learn not only about the challenge(s) they are trying to solve but how it fits into their overall business to deliver the most effective, forward-facing solution. Sampling of successful small challenges solved: -- Custom coding of Shopify notification templates -- Custom Collection filtering by tags -- Custom product attributes by order -- Replaced theme carousel with ADA compliant carousel -- Disabling of Add-to-Cart button until required fields entered Sampling of successful larger projects -- Numerous migrations of WordPress/WooCommerce to Shopify -- Numerous full theme redesigns per mockups and requirements -- Numerous theme updates to Shopify 2.0 version -- Shopify store launch including configuration, product input, and theme customization Sincerely, Thomas Williams
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    Email Marketing
    Responsive Design
    Web Hosting
    PSD to HTML
    JavaScript
    PHP
    HTML5
    CSS 3
    Shopify
    Liquid
  • $45 hourly
    Hi, my name is Dmytro, I'm .Net developer form Ukraine (UTC+2). I have been working as a developer from 2012. Starting as Junior developer, now I am a Senior Developer. It is not a problem for me to combine research, architecture and development. Here is a list of technologies I have experience with: ✓ OOP and System Design (7+ years); ✓ Theoretical knowledge and practical experience with design patterns; ✓ Asynchronous and multithreading development (TPL); ✓ Rest API design, architecture, implementation and integration; ✓ .NET Desktop (WPF) (5+ years); ✓ Telerik and DevExress frameworks for WinForms and WPF (5+ years); ✓ .NET / .NET Core C# (7+ years); ✓ XML, XSLT, Serialization/Deserialization (XML, Binary, JSON); ✓ ASP.NET MVC / Web API (4+ years); ✓ ASP.NET Core; ✓ SMS integration (Twilio, Plivo, SMSru); ✓ Email integration (SendGrid, MailGun, Gmail, custom SMTP); ✓ WCF and WebServices; ✓ Entity Framework; ✓ LINQ; ✓ Database architect and optimization including Microsoft SQL (5+ years); ✓ Git; ✓ Visual Studio;
    vsuc_fltilesrefresh_TrophyIcon SQL
    Standalone Application
    JSON
    Windows Presentation Foundation
    Windows Forms
    XAML
    Computer Network
    C#
    .NET Framework
    DevExpress
    Windows App Development
    Algorithm Development
    .NET Core
    Microsoft Azure
    Code Refactoring
  • $50 hourly
    7+ years experience with QlikView and QlikSense development Excellent analytical, communication, organizational and problem-solving skills coupled Working knowledge of SQL/QlikScripting/Data Modeling Experience with development, deployment, and support of large-scale distributed applications Know how to set up Qlik environment based od QDF structure Know Qlik best practices I have big experience in working with big clients (General Electric, Virgin Mobile, Orange, Walmart, Jeronimo-Martins, etc.)
    vsuc_fltilesrefresh_TrophyIcon SQL
    API Integration
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    With an extensive Upwork client history profile and having been Expert-vetted by Upwork as being in the top 1% of freelancers, I look forward to working with you soon! I am an integrations expert and am able to use tools such as Zapier, Microsoft Power Automate (formerly called Flow), and Make(formerly called Integromat), to create API integrations between many different applications. I have a keen understanding of backend data and how to easily get relevant information from one system to another. Integrating systems on the backend helps business workflow to be simplistic, efficient, and fast. I have been working on integrations since 2016, and have linked together numerous CRMs, accounting systems, marketing systems, spreadsheets, etc in a variety of ways, some simple and some extremely complex. Given API documentation, I am able to build custom connections, triggers, and actions in Zapier for many cloud based applications that do not yet have Zapier integration. Additionally, I have excellent skills in mySQL, and reporting tools such as MyDBR. Some of my other skills include Javascript, Airtable, Google Sheets, Google Forms, Fillable PDFs, JotForm, Typeform, Fillout Forms, X2CRM, Excel, Canvas, Planning Center, TeamUnify, Amateur Radio Operator, French language.
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    Automation
    Customer Relationship Management
    Microsoft Power Automate
    Airtable
    Make.com
    Report Writing
    Automated Workflow
    Relational Database
    API
    API Integration
    HubSpot
    Jotform
    Zapier
    JSON
  • $110 hourly
    Everyone believes in the value of data, and I can help you realize that value. My purpose and passion is helping you meet design and performance issues for both operational and BI/analytic data solutions as well as helping you gain valuable insight from your data with data exploration and visualization solutions. I strive to create long-term relationships with clients, helping you to grow with your data rather than quick one-of projects. First defining the need and designing an appropriate solution rather than letting the solution and technology defining the need. I also strongly believe knowledge sharing with employees are the key to an organization's growth and developing employees through training, coaching and mentoring is fundamental to real success. I have mentored many employees in my career and always enjoy opportunities to lead and mentor in the data management space. I look forward to working with you and helping you achieve success with your data.
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    Snowflake
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    Data Management
    Database Design
    SQL Server Integration Services
    Data Analysis
    Business Intelligence
    Power Query
    Tableau
    Data Visualization
    Microsoft Power BI
  • $60 hourly
    Need launch-ready results for your key goals? Need someone who will communicate details clearly and genuinely care about your success? Someone who will be flexible and reliable, whether you're an established enterprise or a startup launching your MVP? I'll be that person for you. Let's get started! ............... Expert-Vetted & Top-Rated Plus by Upwork (Top 1% of freelancers) ............... Services & Results EDTECH - Hundreds of successful projects spanning Moodle v1.x-4.x and Canvas: a) Front- and back- end UX, UI, theme. and plugin enhancement using HTML, CSS, JS/jQuery, PHP, and SQL b) Infrastructure config/optimization and/or hosting, including AWS, auto-scaling, DB, CDN, security, caching, DNS c) LTI 1.3 and 1.1 provider and consumer solutions d) eCommerce B2C and B2B integration using popular tools like Shopify, Stripe, WordPress, WooCommerce, Edwiser Bridge, Zoho, Authorize.net, and Salesforce.com e) SCORM and xAPI customization and debugging, including remote tracking of usage f) Resposive, mobile, cross-device Moodle optimization g) Reporting and metrics integrations and customizations using ChartJS, HighCharts, Klass, Intelliboard, and LearnerScript h) Content creation using Articulate Storyline, Adobe Captivate, iSpring, Elucidat, and platform tools, including custom scripting for unique experiences i) Search UI/UX and engine customization, including integration/configuration of Solr and AI-based search engines j) Activity module customization, for example mobile/responsive design for lesson modules and adjustment of 3rd-party tools like H5P, Poodll, games, and flashcards k) Thousands of minor UX, logic, API, and DB updates using JavaScript, PHP, CSS, SQL, jQuery, and others - Complete LMS/LXP/LTI solutions - Single- and multi- tenant Moodle and Wordpress-based solutions: a) Pre-built Moodle multi-tenant / client platform combing top theme, eCommerce, admin. plugins, and 300+ enhancements; launched for 100 - 100K+ users b) Pre-built LTI 1.3 provider enabling distribution of apps/products to popular K-12 and higher-ed LMS and CMS platforms; other LTI pre-builds also available MARKETING & SALES AUTOMATION - Enterprise automation and migration: a) API-based integration of Shopify and Stripe, as well as Salesforce.com, Freshdesk, Zoho CRM/Subscriptions/Creator, payment processing, and product platforms b) Migration of legacy sales/marketing systems and process to sf.com c) Development of advanced salesforce.com and Zoho workflow rules and components for marketing automation and sales goals - Multiple customized Wordpress (WP) sites serving subscription and one-off information products, including subscription management, payments, and organic search tools/code - WP plugin customization: - Elimination of WP plugin conflicts before and after updates, incl. identifying conflicts in variables across plugins - Elimination of WP malware infections and post-removal server hardening - Migration of WP installs to hosted services like WPEngine - Migration from legacy WP themes to modern, responsive/adaptive themes - Integration of analytics and customer success tools into websites and mobile products (e.g. Google Analytics, Localytics, Evergage) - Integration and customization of eCommerce/cart capabilities, including Shopify, Edwiser Bridge, WooCommerce, aMember, PayPal and other services / APIs - Development and updates of Unbounce and custom PHP-based landing pages responsible for generating millions of views each month for direct and affiliate traffic - Data / analytics: Development of Excel VBA apps and macros to analyze millions of data points for financial research, migrating 50K+ customer and invoice records from Quickbooks to Netsuite, and more Technical Skills • Product: PHP, HTML, CSS, Javascript, jQuery, Angular, Node.js, AJAX, ASP.NET VB/C#.NET, Objective-C, VBA, Java, MSSQL, MySQL, Wordpress, Moodle, IOMAD, Totara, Canvas, SCORM, xAPI, Limelight, Brightcove, Vimeo API, Sublime, Articulate Storyline, Elucidat, Captivate, Balsamiq, XD, Github, Gitlab, Bitbucket, JIRA, Trello, Asana, Zendesk, Desk.com, HelpScout, Evergage, Zapier, VWD, Eclipse, Xcode, TortoiseSVN, Photoshop, Fireworks, InDesign • Sales/marketing: Salesforce and Zoho CRMs (incl. workflow/coding), Pardot, Google analytics/adwords, Shopify, Stripe, PayPal, WooCommerce, Intercom.io, Unbounce, MailChimp, SendGrid, MagnetMail, BigCommerce, aMember, funnel design, multi-channel automation incl. email marketing, SEO, PPC, outbound/cold call scripting • Systems: Linux, Apache, AWS, Azure, Rackspace, TCP/IP, DNS, Email delivery incl. SPF, DKIM, DMARC compliance, Windows Server, IIS, Unix, Twilio, RingCentral, Box.net, Active Directory, Exchange ............... Rates Development: $60/hr Strategy/guidance/architecture only: $130/hr
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    Elearning LMS Consulting
    Moodle
    Shareable Content Object Reference Model
    Adobe XD
    Elearning
    Amazon Web Services
    PHP
    JavaScript
    Instructure CANVAS
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    Learning Management System
    Authorize.Net
    WordPress
    Shopify
  • $75 hourly
    A highly skilled and experienced Full Stack Developer with over 10 years of expertise in Python, Flask, FastAPI, Django, Swift, and iOS development. Proven track record in leading development teams and delivering high-quality web and mobile applications. Seeking a long-term opportunity to contribute to the success of projects, utilizing my strong back and front-end development skills to meet client needs. Technical Skills Programming Languages: • Python (Django, Tornado, Flask, FastAPI) • Swift (iOS development) • DHTML (HTML, CSS3, JavaScript) Frontend Technologies: • Vue.js • jQuery Backend Technologies: • FastAPI • Django ORM • Flask • Django REST Framework • SQLAlchemy • AsyncIO Databases: • MySQL • PostgreSQL • MongoDB API & Tools: • IBM Watson Assistant • Google DialogFlow • Stripe Integration and Subscription Flow DevOps: • AWS Infrastructure (EC2, ECS, Lambda) • Google Cloud Platform • AliCloud Other Tools: • Docker • New Relic • uWSGI Experience Team Leader / Full Stack Developer • Led multiple development teams of 3 to 8 developers in various projects. • Developed websites, web services APIs, and mobile applications using Flask, FastAPI, and Django. • Developed data transformation pipelines using Python, Celery and Ray • Worked on face recognition, AR and Natural Language processing technologies • Implemented both back-end and front-end components, enabling efficient team collaboration and task understanding. • Assisted in the development of high-quality applications from scratch to production. • Helped clients build MVPs within a week to validate their ideas. • Provided support and solutions to clients with previously failed applications or those left incomplete by previous developers. Education - Bachelor degree in computer science and economics - Irkutsk state univercity - Graduated at 2012 Availability & Preferences • Flexible working hours • Willing to work closely with teammates or freelancers • Seeking long-term projects and client relationships Please feel free to contact me for further information or to discuss your project requirements.
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    Django
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    API Development
    AWS Fargate
    Stripe
    MySQL Programming
    PostgreSQL Programming
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    iOS Development
    iOS
    Python
    Swift
  • $100 hourly
    I love MS Access and VBA, they've been my passion for over 25 years and I've become a pro at developing amazing apps and automating. My apps are top quality: user-friendly, very well thought out, packed with functionality yet simple to use, and are developed with an eye towards minimal clicking and thinking for the user. Automation and streamlining is a constant theme in everything I do. I believe that you and people in your company shouldn't do ANY manual repeating tasks because they can all be automated. I'm excellent at automation, I will ask a ton of questions to learn your workflow and will then develop an app that will do most of your work for you. I can also do anything you need when it comes to updating existing MS Access applications, automating your workflow, converting Excel sheets to MS Access applications, converting MS Access applications to SQL or to newer versions of MS Access, and writing Excel macros. I'm quick to reply to messages I'm easy to work with, no condescension here :) I have many libraries of reusable VBA code, forms, and reports, which greatly speed up development
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    Database Design
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    MySQL
    Data Migration
    Data Analysis
    Microsoft Access
    Microsoft Access Programming
    Oracle PLSQL
    Visual Basic for Applications
    Microsoft Excel
    Automation
  • $105 hourly
    ➤ Experienced and certified Power BI Analyst with advanced skills in SQL, Power Query (M), and DAX. ➤ Excellent communication skills and a commitment to client satisfaction. ➤ With five years experience using Power BI and 18 years as a software developer, I have a proven track record of unifying complex data sources and creating effective visualizations. ➤ Familiarity with healthcare, financial, and retail industries and the KPIs that drive them ➤ Expert in integrating dashboards into existing applications via Power BI Embedded and the Power BI Service
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    SQL Programming
    Microsoft Power BI Development
    Microsoft SQL Server
    ETL
    KPI Metric Development
    Microsoft Azure
    Data Science
    Microsoft Power BI Data Visualization
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    Business Intelligence
    Microsoft Power BI
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How to Hire Top SQL Developers

How to hire SQL developers

A SQL programmer designs tables, writes queries, and ensures that these queries perform at optimal speeds. Most SQL developers are either database administrators or experts in managing database development. There are different flavors of SQL depending on the platform you use, but they all perform the same basic functions—retrieve, add, edit, and delete database data. And a SQL programmer will be well-versed in all of these functions. Typical tasks for a SQL programmer include:
  • Reviewing query performance and optimizing code
  • Writing queries used for front-end applications (websites, desktop applications, or cloud apps)
  • Designing and coding database tables to store the application’s data
  • Data modeling to visualize database structure
  • Working with application developers to create optimized queries
  • Creating database triggers for automation, e.g., automatic email notifications
  • Creating table indexes to improve database performance
  • Programming views, stored procedures, and functions

How to shortlist SQL specialists

If you need someone to design a database for you, work with your website developers, or optimize a slow database, you’re looking for a SQL programmer. To attract the best talent, you should clearly define what you need and what you’re looking for.
  • Know what database platform you want to use. The three most common are SQL Server, MySQL, and Oracle. If you have an existing application, find out what database platform you use by asking your developer or contacting your host provider.
  • What challenge is your SQL programmer solving, or helping to solve? Clearly explain the tasks and needs of the project. Identify the specific services and deliverables with enough detail so that freelancers can determine that they’re able to perform the work.
  • Define what level of experience your project requires.
    • Entry-level SQL developers can create simple queries that don’t require too much advanced code.
    • An intermediate-level SQL developer can typically code easy to advanced queries and even perform some database maintenance and optimization for performance. An intermediate-level SQL programmer can be great for simple websites that don’t have too much overhead.
    • An expert SQL developer should be able to do it all—optimize your queries when your website is too slow due to database performance, write queries for heavy traffic databases, and design tables and indexes for the best database architecture and performance.
After posting a detailed and thought-out project description that defines your SQL developer’s tasks, you should receive several proposals from freelancers across the globe with a variety of skill sets. How do you choose the right one for your project? Experience is especially important with SQL programmers because they create the queries that form your website’s output. Gauge their experience level both by reviewing previous work and asking specific questions when you interview them. Most programmers are used to answering technical questions as part of the interview process. You may choose to ask your freelancer some basic SQL programming interview questions to judge their level of experience. For SQL in particular, it can be difficult for a freelancer to display portfolio items, but you can review the items they uploaded to their profile and their previous work experience.

How to write a job description for a SQL developer

Below is a sample of how a project description may look. Keep in mind that many people use the term “job description,” but a full job description is only needed for employees. When engaging a freelancer as an independent contractor, you typically just need a statement of work, job post, or any other document that describes the work to be done.
  1. Project Title
  2. Project Overview
  3. XYZ Company is looking for a SQL programmer to create and optimize database queries that run a small e-commerce store cloud application. We need someone to handle queries for the database and return data sets for the frontend.
Deliverables include:
  • Determining what data must be returned to the application and writing queries for it
  • Optimizing any existing queries to speed up performance
  • Creating and designing tables when new new modules are added to a software product
  • Reviewing current database design and making suggestions for better performance
  • Creating table indexes that optimize query speeds
  • Defining triggers on necessary tables
  • Determining the right stored procedures, views, and functions for the application
  • Deadline for deliverables: All work must be completed by XYZ date.
  • Skills:
    • Database administration
    • Table design including normalization
    • Database backups and recovery is a plus but not necessary
    • Understanding the way databases work with cloud applications is also a plus

SQL FAQs

What is SQL?

Structured query language (SQL) is the foundation for back-end database programming and design. It’s the language that allows us to access and manipulate databases, execute queries, retrieve data, edit data, and insert new data—essentially, everything that makes databases interactive, not static. If you want your website or application to be dynamic and interactive, you’ll need a SQL developer to design and program your database.

Why hire a SQL developer?

Some SQL programmers assist the database administrator with standard maintenance, but this is not usually required. However, having experience in database administration and maintenance is a great addition to the standard skillset of a SQL programmer. If your database administrator is on vacation or leaves the company, the SQL programmer can easily fill in.

Common SQL mistakes

SQL (structured query language) is a simple language, but it’s not so simple when you’re working with data sets that contain millions of records. When you work with mid- to large-size tables, writing top-performing SQL statements is a priority. Before you sit down to write your SQL statements for any platform—Oracle, SQL Server, MySQL, or any others—here are the top 10 common SQL programming mistakes to avoid.

1. Forgotten primary keys

Every table requires a primary key for performance. If you don’t have a primary key in any table, your tables don’t follow standard SQL requirements and performance suffers. Primary keys are automatically set as clustered indexes, which speeds up queries. They are always unique, so you can use an auto-incremented numeric value if you have no other column in the table that meets the unique requirement. Primary keys are your first step to relational databases.

They link to foreign keys in relational tables. For instance, if you have a table that has a list of customers, the “CustomerId” column would be unique to every customer. This could be your primary key column. Your CustomerId value would then be placed in the Orders table to link the two tables together. Always use a primary key in every table you create regardless of its size.

2. Poorly managed data redundancy

Data redundancy is good for backups but not for table data. Each table should contain a unique data set that doesn’t repeat data in other table locations. This is one of the more difficult ideas for a new SQL developer to follow. It’s very easy to forget normalization rules and repeat data across multiple tables for conveniences, but it’s not necessary and represents poor table design. For instance, suppose you have a customer table that contains the customer’s address. Since the address relates to the customer, it’s in the proper location. You then create an “Order” table and add the customer’s address in the Order table.

This type of data redundancy is poorly designed. The Customer and Order table can link together using relationships across primary and foreign keys. What happens when you forget to update the customer’s address in the Order table? The result is that you now have two addresses for the customer and you don’t know which one is accurate.

3. Avoid NOT IN or IN and use JOIN instead 

NOT IN and IN statements are not well optimized. They are convenient, but usually they can be replaced by a simple JOIN statement.

4. Forgotten NULL vs. empty string values

The NULL vs. empty string debate between database administrators has been ongoing for decades. You can choose to use NULL values when no value is present or you can use actual literal values such as zero-length strings or 0 integer values. What you use in the database should be uniform across all tables or queries can get messy. Remember that NULL values aren’t the same as, for instance, a zero-length string, so your queries must account for these values if there is no standard in your table design.

When you determine what you want to use, make sure your queries account for these values. For instance, if you allow NULLs for a user’s last name, you must query using the NULL filter (either NOT NULL or IS NULL) in your clauses to include or exclude these records.

5. The asterisk character in SELECT statements

Always define the columns you want to return in your queries. This standard is for performance and security reasons. Take the following query, for example. SELECT * FROM Customer The query returns all customer values including any sensitive data you might keep in the table. What if you keep the customer’s password or social security number in the table?

Hopefully, these values are encrypted, but even having the hashed value can help hackers. It’s also a performance issue if you have dozens of columns in the table. Instead of the above query, always define each column. The following statement is an example. SELECT CustomerId, FirstName, LastName FROM Customer The above statement defines each column and limits the size of the record set as well as what a hacker can see should there be a data breach.

6. Looping with too many cursors

Cursors, the looping structures in the SQL language, are the bane of database performance. They allow you to loop through millions of records and run statements against each one individually. While this may sound like an advantage, it can destroy database performance. Loops are common in programming languages, but they’re inefficient in SQL programming.

Most database admins reject SQL procedures with cursors implemented. It’s best to write the procedure in another way to avoid adversely affecting database performance if possible. Most cursors can be replaced by a well-written SQL statement. If you can’t avoid it, then cursors should be kept to scheduled jobs that run during off-peak hours. Cursors are used in reporting queries and data transformation jobs, so they can’t always be avoided. Just limit them as much as possible in production databases that perform daily queries against your database.

7. Data mismatches in field assignment procedures

When you declare your table columns, you must give each column a data type. Make sure this data type covers all the necessary values you need to store. Once you define a data type, you can only store that type of value in the column. Always account for what you need to store when you design your tables. This includes writing queries—when you write your queries and pass parameter values to a stored procedure, the variable must be declared with the right data type. Variables that don’t represent the column data type will also throw errors or truncate data in the process.

8. Logical OR and AND operations

When writing your queries, it’s easy to miss simple logic order. AND and OR statements can greatly change a data set. You can avoid common SQL bugs by either using parenthesis or organizing your statements to represent the logic that should be applied.

9. Subqueries must return one record

Subqueries aren’t an optimal way to write SQL statements, but sometimes they can’t be avoided. When you use subqueries, they must always return one record or your query will fail.

10. JOIN on indexes

A table should always be well indexed, and you can take advantage of these performance enhancements by using the JOIN statement on columns assigned to an index. In the previous examples, we used the primary and foreign keys of a table. The primary key column is always an index, so you don’t need to worry about performance there. However, the foreign key should have an index on it as well. Any JOIN statements you use should have an index set on the column. If there is no index, consider adding one to the table. Avoid these ten SQL pitfalls, and you’ll be on your way to creating a fast, efficient database for any small, medium, or large online business.

Tips and best practices for SQL programmers

Structured query language (SQL) is the primary language for databases. Whatever relational database platform you decide to use, you’ll need to use SQL to edit, insert, delete, and query records within the database. Each platform has small differences between their respective SQL syntax, but logic and development are still similar. The language is different than NoSQL, which has similarities but mainly different syntax. Here are some tips and best practices for any SQL development project.

1. Think about relationships

The SQL language is the language of relational databases. You need to build tables based on relationships without creating “orphans.” Orphans are tables that don’t have a relationship with any other table and are poor database design. Each table should have a relationship with another, so when you query the database for records, you can join the tables together through their designated relationship.

You build a relationship through primary and foreign keys. For instance, suppose you have a customer table and an order table. Without the customer ID in the order table, the order table is orphaned. By placing the customer ID in the order table, you now have a relationship between the two tables that you can use to create queries.

2. Always consider performance, even if the query seems simple

Just because your SQL data set has few records currently doesn’t mean the data set won’t grow significantly after you move it to production. You should join tables on indexes and always have a primary key in each table.

One common mistake is to run a poorly performing query in development when the system has no users querying and very few records. The query runs fast, because there’s no load on the database server. Then, when the query is promoted to production and run in a busy environment, the query performs poorly and undermines site performance. Always consider performance even if the query seems like it won’t need many resources from the database server.

3. Use table aliases for easier reading

Let’s say you’re a developer who needs to maintain someone else’s code. Or, you’re a business owner who needs to hire a SQL developer to fill in the gaps with a specific project. The SQL developer can pick up where another developer left off much quicker if the code uses aliases and is well formatted.

Aliases shorten the name of a table and make it easier to read and determine the logic in a SQL statement. When you build a database, always consider the way the code is written. It should be easy for you and another developer to determine its logic and data set. Poorly coded SQL code can lead to bugs should another developer need to edit it.

4. Be specific in your SELECT clauses

In any common SQL language, the asterisk ( * ) tells the database engine to return all columns within a table. There are several issues with this habit. The first issue is security. If a hacker is able to use a SQL injection attack on your database, it could leave every column available for theft. If you have customer passwords stored in the table, the attacker can expose passwords.

The second issue is performance. If you have a million records returned from a query, you affect performance when you return a couple dozen columns rather than the few that you need.

The third issue is that it’s difficult to determine what data will be returned. If you specify columns in your SELECT queries, you know exactly which ones are returned to the front-end application. For these three reasons, always specify the columns you want to return and avoid using the “all” or asterisk character in your queries.

5. Use NOCOUNT for large batch queries

When you perform ad hoc queries such as updates and inserts on your database, the engine first performs the action, then gives you a count of the number of records that were affected. This is great for one-off changes when you want to confirm that changes were made to a specific number of records, but it shouldn’t be done on queries that run regularly. When NOCOUNT isn’t used, the database must count the number of rows that were affected. This isn’t a necessary count with production queries that run regularly. Use NOCOUNT at the top of your stored procedures or ad hoc queries to improve performance.

6. Avoid dynamic SQL

SQL injection is one of the most common attacks on the web. This type of attack leads to severe data breaches that expose millions of records to an attacker. Extremely strategic SQL injection attacks can even elevate permissions for the attacker to give them administrative rights on the database server. Dynamic SQL is a type of coding that builds a SQL statement based on input from a user.

Typically, it’s done on the front-end application side, but some SQL developers use it too. Dynamic SQL should be avoided at all costs—it’s this type of development that leads to SQL injection exposure. If you absolutely need to use dynamic SQL, you should “scrub” data input and make good attempts to detect malformed SQL statements. You can use third-party tools or integrated tools available with some languages. For instance, the C# language has the TSqlParser class to help programmers identify SQL injection in a dynamic SQL environment.

7. Don’t forget Object-Level security

Security should always be a priority when designing a database regardless of the platform you use. Object-level permissions provide security based on the user and what the account can access. For instance, you want to use a separate user name for all of your databases and give them access to the database accordingly.

By using this method, if a hacker gains access to the account, they’ll only be able to access one database and not the entire server. You can be even more specific with object-level permissions. This tells the database the exact tables and even columns that the user can access. By using object-level permissions, you limit the amount of exposure if an attacker is successful at SQL injection. For instance, suppose you store social security numbers in the database. A public-facing user application should never have access to this information. You only want internal employees to have access. So, you create a public-facing user account and give it object-level permissions to the table, then access rights to specific columns, excluding the social security column. If a hacker gains access to this account, they won’t be able to view social security numbers, which limits your data breach exposure, risk, and damages.

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