SQL指南-别名
使用SQL,可将别名用于列表和表的名称。
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列的别名
语法为:
SELECT column AS column_alias FROM table |
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表的别名:
语法为:
SELECT column FROM table AS table_alias |
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语法:使用列的别名
这个表 (Persons):
LastName | FirstName | Address | City |
---|---|---|---|
Hansen | Ola | Timoteivn 10 | Sandnes |
Svendson | Tove | Borgvn 23 | Sandnes |
Pettersen | Kari | Storgt 20 | Stavanger |
和这个SQL语句:
SELECT LastName AS Family, FirstName AS Name FROM Persons |
返回这个结果:
Family | Name |
---|---|
Hansen | Ola |
Svendson | Tove |
Pettersen | Kari |
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示例: 使用表的别名
这个表 (Persons):
LastName | FirstName | Address | City |
---|---|---|---|
Hansen | Ola | Timoteivn 10 | Sandnes |
Svendson | Tove | Borgvn 23 | Sandnes |
Pettersen | Kari | Storgt 20 | Stavanger |
和这个SQL语句:
SELECT LastName, FirstName FROM Persons AS Employees |
返回这个结果:
Employees表:
LastName | FirstName |
---|---|
Hansen | Ola |
Svendson | Tove |
Pettersen | Kari |