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SQL Tutorial

SQL is a standard language for storing, manipulating and retrieving data in databases.

Our SQL tutorial will teach you how to use SQL in: MySQL, SQL Server, MS Access, Oracle, Sybase, Informix, Postgres, and other database systems.

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示例 in Each Chapter

With our online SQL editor, you can edit the SQL statements, and click on a button to view the result.


SELECT * FROM Customers;
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Click on the "来试试吧" button to see how it works.

SQL 练习

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Insert the missing statement to get all the columns from the Customers table.

 * FROM Customers;

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SQL 示例

Learn by examples! This tutorial supplements all explanations with clarifying examples.

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SQL测验 Test

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SQL 参考

At W3Schools you will find a complete reference for keywords and function:

SQL Keyword 参考

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SQLServer Functions

MS Access功能



Data types and ranges for Microsoft Access, MySQL and SQL Server.


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