数据表修改

2018-02-05  本文已影响0人  mejhwu

添加单列

ALTER TABLE table_name ADD [COLUMN] column_name column_definition [FIRST | AFTER colomn_name]

添加多列

ALTER TABLE table_name ADD [COLUMN](column_name column_definition, ...)

删除列

ALTER TABLE table_name DROP column_name1, DROP column_name2, ...

添加主键约束

ALTER TABLE table_name ADD[CONSTRAINT [symbol]] PRIMARY KEY [index_type] (index_column_name,...)

添加唯一约束

ALTER TABLE table_name ADD [CONSTRAINT [symbol]] 
UNIQUE [INDEX|KEY] [index_name] [index_type](index_column_name,...)

添加外键约束

ALTER TABLE table_name ADD [CONSTRAINT [symbol]] 
FOREIGN KEY [index_name] (index_column_name,...) reference_definition

添加/删除默认约束

ALTER TABLE table_name ALTER [COLUMN] column_name {SET DEFAULT literal | DROP DEFAULT}

删除主键约束

ALTER TABLE table_name DROP PRIMARY KEY

删除唯一约束

ALTER TABLE table_name DROP {INDEX | KEY} index_name

删除外键约束

ALTER TABLE table_name DROP FOREIGN KEY kf_name

修改列定义

ALTER TABLE table_name 
{MODIFY | CAHNGE} [COLUMN] column_name column_definition [FIRST | AFTER column_name]

修改列名称

ALTER TABLE table_name 
MODIFY [COLUMN] old_column_name new_column_name  column_definition [FIRST | AFTER column_name]

数据表更名

ALTER TABLE table_name RENAME [TO|AS] new table_name

RENAME TABLE table_name TO new_table_name [, table_name2 TO new_table_name2]...
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