核心代碼:
複製代碼 代碼如下:
ALTER TABLE 表名 AUTO_INCREMENT = 設定的值
MySQL ALTER文法中ALTER [IGNORE] TABLE tbl_name alter_spec [, alter_spec ...]
複製代碼 代碼如下:
alter_specification:
ADD [COLUMN] create_definition [FIRST | AFTER column_name ]
or ADD INDEX [index_name] (index_col_name,...)
or ADD PRIMARY KEY (index_col_name,...)
or ADD UNIQUE [index_name] (index_col_name,...)
or ALTER [COLUMN] col_name {SET DEFAULT literal | DROP DEFAULT}
or CHANGE [COLUMN] old_col_name create_definition
or MODIFY [COLUMN] create_definition
or DROP [COLUMN] col_name
or DROP PRIMARY KEY
or DROP INDEX index_name
or RENAME [AS] new_tbl_name
or table_options
eg:
mysql> alter table topics change hotico hot_count int(4);
mysql> alter table topics alter hot_count set default 1;
補充:
加索引
mysql> alter table 表名 add index 索引名 (欄位名1[,欄位名2 …]);
例子: mysql> alter table employee add index emp_name (name);
加主關鍵字的索引
mysql> alter table 表名 add primary key (欄位名);
例子: mysql> alter table employee add primary key(id);
加唯一限制條件的索引
mysql> alter table 表名 add unique 索引名 (欄位名);
例子: mysql> alter table employee add unique emp_name2(cardnumber);
MySQL ALTER文法運用:查看某個表的索引
mysql> show index from 表名;
例子: mysql> show index from employee;
刪除某個索引
mysql> alter table 表名 drop index 索引名;
例子: mysql>alter table employee drop index emp_name;
修改表:增加欄位:mysql> ALTER TABLE table_name ADD field_name field_type;
查看錶:mysql> SELECT * FROM table_name;
修改原欄位名稱及類型:mysql> ALTER TABLE table_name CHANGE old_field_name new_field_name field_type;
刪除欄位:MySQL ALTER TABLE table_name DROP field_name;