Mysql、SqlServer和Oracle 添加、修改、删除 字段总结
1、添加 添加单列: ALTER TABLE 表名 ADD 列名 数据类型 添加多列: ALTER TABLE 表名 ADD 列名1 数据类型1,列名2 数据类型2 2、修改 修改单列数据类型: ALTER TABLE 表名 ALTER COLUMN 列名 数据类型 同时修改多列数据类型: 不支持 3、删除 删除单列: ALTER
1、添加
- 添加单列:
- 添加多列:
ALTER TABLE 表名 ADD 列名1 数据类型1,列名2 数据类型2
2、修改
- 修改单列数据类型:
ALTER TABLE 表名 ALTER COLUMN 列名 数据类型
- 同时修改多列数据类型:
不支持
3、删除
- 删除单列:
ALTER TABLE 表名 DROP COLUMN 列名
- 删除多列:
ALTER TABLE 表名 DROP COLUMN 列名1,列名2
4、同时添加和修改多列:
不支持,每次只能进行一种操作.
Oracle(PL/SQL):
1、添加
- 添加单列:
ALTER TABLE 表名 ADD 列名 数据类型
- 添加多列:
ALTER TABLE 表名 ADD ( 列名1 数据类型1,列名2 数据类型2)
2、修改
- 修改单列数据类型:
ALTER TABLE 表名 MODIFY 列名 数据类型
- 同时修改多列数据类型:
ALTER TABLE 表名 MODIFY ( 列名1 数据类型1,列名2 数据类型2)
3、删除
- 删除单列:
ALTER TABLE 表名 DROP COLUMN 列名
- 删除多列:
ALTER TABLE 表名 DROP (列名1,列名2)
4、同时添加和修改多列:
ALTER TABLE 表名 ADD ( 列名1 数据类型1,列名2 数据类型2) MODIFY ( 列名3 数据类型3,列名4 数据类型4)
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