Update 语句
Update 语句用于修改表中的数据。
语法:
Update 表名称 SET 列名称 = 新值 Where 列名称 = 某值
Person:
LastName
|
FirstName
|
Address
|
City
|
Gates
|
Bill
|
Xuanwumen 10
|
Beijing
|
Wilson
|
|
Champs-Elysees
|
|
更新某一行中的一个列
我们为 lastname 是 "Wilson" 的人添加 firstname:
Update Person SET FirstName = 'Fred' Where LastName = 'Wilson'
结果:
LastName
|
FirstName
|
Address
|
City
|
Gates
|
Bill
|
Xuanwumen 10
|
Beijing
|
Wilson
|
Fred
|
Champs-Elysees
|
|
更新某一行中的若干列
我们会修改地址(address),并添加城市名称(city):
Update Person SET Address = 'Zhongshan 23', City = 'Nanjing'
Where LastName = 'Wilson'
结果:
LastName
|
FirstName
|
Address
|
City
|
Gates
|
Bill
|
Xuanwumen 10
|
Beijing
|
Wilson
|
Fred
|
Zhongshan 23
|
Nanjing
|