ALTER
| 操作 |
语法 |
示例 |
注意 |
| 修改表名 |
ALTER TABLE table_name RENAME TO new_table_name |
alter table t1 rename to t2; |
|
| 增加字段(列) |
ALTER TABLE table_name ADD field_name field_type |
alter table testsuper add aclomn varchar(10) default null; |
|
| 修改字段 |
ALTER TABLE table_name MODIFY field_name field_type |
alter table testsuper modify aclomn varchar(20); |
|
| 修改字段名称及类型 |
ALTER TABLE table_name CHANGE old_field_name new_field_name field_type; |
alter table testsuper change aclomn bclomn int; |
修改一个字段的名称，此时一定要重新指定该字段的类型 |
| 删除字段 |
ALTER TABLE table_name DROP field_name; |
alter table testsuper drop bclomn; |
|
| 添加主键索引 |
ALTER TABLE `table_name` ADD PRIMARY KEY ( `column` ) |
alter table testsuper add primary key (T_ID); |
|
| 添加唯一索引 |
ALTER TABLE `table_name` ADD UNIQUE ( `column` ) |
alter table testsuper add UNIQUE (T_IE); alter table testsuper add UNIQUE index u1 (T_ID,TC_IE);//联合唯一索引别名为u1的联合索引 |
|
| 添加普通索引 |
ALTER TABLE `table_name` ADD INDEX ( `column` ) |
alter table testsuper add index (T_IF); |
|
| 添加全文索引 |
ALTER TABLE `table_name` ADD FULLTEXT ( `column` ) |
alter table testsuper add fulltext (T_IH); |
|
| 添加联合索引 |
ALTER TABLE `table_name` ADD INDEX index_name ( `column1`, `column2`, `column3` ) |
alter table testsuper add index st (T_IM,T_IN); |