什么是SQL？
SQL is one of the languages most essential to facilitating data management and online transactions.
雇用SQL Specialists
Freelancer.com has many SQL professionals on hand to help you with whatever your issue is.
Get Free Quotes
- 服务于
雇用SQL Specialists
SQL specialists are the kinds of people that can truly scale a company by changing the way that they manage and stream data. Speak to one immediately at Freelancer.com for free!
威客的作品集
Build contact forms into a website with emails sent automatically to enquirers upon completion. Perfect for businesses needing to quickly quote the cost of work and projects.
Build Website to Capture Leads
$40 USD
Switching a site to become mobile responsive. Why spend hours studying to how to do it and risking mistakes when you can get it done in minutes instead?
Make a Website Mobile-Responsive
$10 USD
Mobile-responsive website design for a business buying and reselling 2nd hand cars. Intuitive website designs help you turn visitors into buyers and get more sales without spending more on marketing.
Design Mobile Responsive Website
$114 USD
威客可以为您完成更多的工作
-
让威客来分担您的工作
将更多精力集中在您擅长的领域以获得更高的产出。
-
价格合理公道
您可以找到设计师，开发人员，营销人员和作家。
-
不会因为雇人不善而后悔
阅读真实评论并选定最佳人选
As Featured in
世界上最大的市场
数百万用户，从小型公司到大型集团，企业家到创业者， 都使用Freelancer来实现他们的商业梦想。
63.3百万
已注册用户总数
22.1百万
已发布的工作总数
FEATURED FREELANCER
Excellent work, super fast, super quality and understood the brief perfectly!
If you're looking for a talented web developer you'll find people like Charchit to help you accomplish your needs.
Wordpress Membership Website Building
USD $350
在Freelancer上雇用a SQL Developer
Structured query language, more widely recognized as SQL, is a special purpose programming language and a standard language for relational database management systems. SQL is effective in communicating with and managing data held in a relational database. A majority of database products available are based on SQL programming language, although customization of the standard language using proprietary extensions is common. Oracle, Sybase, Microsoft SQL Server, Access and many other leading databases use SQL.
SQL is primarily a declarative language, a non-imperative programming approach where appropriate results are identified as opposed to explicit commands that must be conducted. However, SQL does also include some procedural elements. SQL incorporates three different language varieties, data definition, data manipulation and data control all contribute to SQL outcomes.
Donald D Chamberlin and Raymond F Boyce are credited with the development of SQL in the early 1970s. Experts in relational algebra and tuple relational calculus, the pair created the programming type to communicate with, retrieve and manipulate data from IBM's original database. They termed the language SEQUEL originally, referring to structured English query language, although a trademark conflict with a UK company saw it later changed to SQL.
Oracle, at the time named Relational Software, observed the concepts of Chamberlin and Boyce and saw a widespread application for the programming language. They developed their alternate version of SQL holding aspirations of securing business with US Government agencies. They began selling SQL RDBMS in June 1979.
The American National Standards Institute (ANSI) and International Organization for Standardisation (ISO) confirmed SQL as a standard in 1986 and 1987 respectively. Since then SQL has continued to evolve to include a larger set of features.
SQL programming language includes several language elements. Clauses are integral components of statements and queries. Expressions combine values operators and SQL functions. Predicates are used to limit the effect of statements and queries or change program flow. A query is an inquiry into the database using the SELECT statement. Statements control transactions, connections, sessions, perform diagnostics and more.
If you are searching for an SQL programmer qualified in computer science, management information systems or information science, or you require a professional employee adept at logical thinking, problem-solving, with a detail-oriented approach and strong programming skills, you should consider the services of a freelancer.
Freelancer.com is a crowdsourcing marketplace and home to thousands of computer programming specialists well versed in SQL programming language. Freelancer.com allows potential employers to post jobs or projects that freelancers can bid for selection. Freelancer is free to join, post a project and receive bids. Once you've posted a project, you'll receive bids within minutes. Employers can review a freelancer’s portfolio and discuss project requirements directly before making a decision on the perfect candidate. With over 19 million users, you'll be sure to find the perfect match for your project.
With Freelancer, you get access to the best talent from around the world, and at an affordable price too! Post a project today to find the perfect freelancer for your next SQL project.
运作流程
-
1. 发布工作
告诉我们您的任务。
-
2. 选择威客
您很快就会收到竞标，并且可以从中挑选最棒的威客。
-
3. 追踪过程
随时和您的威客聊天并且浏览他们的作品。
-
4. 安全支付
只有当您完全满意时才需付款。
