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SQL 教程

SQL HOME SQL Intro SQL Syntax SQL Select SQL Select Distinct SQL Where SQL And, Or, Not SQL Order By SQL Insert Into SQL Null Values SQL Update SQL Delete SQL Select Top SQL Min and Max SQL Count, Avg, Sum SQL Like SQL Wildcards SQL In SQL Between SQL Aliases SQL Joins SQL Inner Join SQL Left Join SQL Right Join SQL Full Join SQL Self Join SQL Union SQL Group By SQL Having SQL Exists SQL Any, All SQL Select Into SQL Insert Into Select SQL Case SQL Null Functions SQL Stored Procedures SQL Comments SQL Operators

SQL 数据库

SQL Create DB SQL Drop DB SQL Backup DB SQL Create Table SQL Drop Table SQL Alter Table SQL Constraints SQL Not Null SQL Unique SQL Primary Key SQL Foreign Key SQL Check SQL Default SQL Index SQL Auto Increment SQL Dates SQL Views SQL Injection SQL Hosting SQL Data Types

SQL 参考手册

SQL Keywords MySQL Functions SQL Server Functions MS Access Functions SQL Quick Ref

SQL 实例

SQL Examples SQL Quiz SQL Exercises

SQL 教程

SQL 是用于访问和处理数据库的标准的计算机语言。

在本教程中,您将学到如何使用 SQL 访问和处理数据系统中的数据,这类数据库包括:Oracle, Sybase, SQL Server, DB2, Access 等等。

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每章中的实例

使用我们的在线 SQL 编辑器,您可以编辑 SQL 语句,然后单击按钮查看结果。

实例

SELECT * FROM Customers;
亲自试一试 »

点击 "Try it Yourself" 按钮查看运行结果。


SQL 练习

学习训练

习题:

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

 * FROM Customers;



SQL 实例

通过实例来学习,本教程将通过实例来补充说明解释。

See All SQL Examples


SQL 测验

Test your SQL skills at W3Schools!

Start SQL Quiz!


SQL 参考手册

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

SQL Keyword Reference

MYSQL Functions

SQLServer Functions

MS Access Functions

SQL Quick Reference


SQL Data Types

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

SQL Data Types