显示表的列信息。完整语法如下：
SHOW [FULL] COLUMNS FROM tbl_name [FROM db_name] [like_or_where]
实例：使用 show columns 查看 city 表格的结构。如下：
mysql> show columns from city; +-------------+----------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------+----------+------+-----+---------+----------------+ | ID | int(11) | NO | PRI | NULL | auto_increment | | Name | char(35) | NO | | | | | CountryCode | char(3) | NO | MUL | | | | District | char(20) | NO | | | | | Population | int(11) | NO | | 0 | | +-------------+----------+------+-----+---------+----------------+ 5 rows in set (0.01 sec)
使用 show full 显示表格详细信息。如下：
mysql> show full columns from city; +-------------+----------+-------------------+------+-----+---------+----------------+---------------------------------+---------+ | Field | Type | Collation | Null | Key | Default | Extra | Privileges | Comment | +-------------+----------+-------------------+------+-----+---------+----------------+---------------------------------+---------+ | ID | int(11) | NULL | NO | PRI | NULL | auto_increment | select,insert,update,references | | | Name | char(35) | latin1_swedish_ci | NO | | | | select,insert,update,references | | | CountryCode | char(3) | latin1_swedish_ci | NO | MUL | | | select,insert,update,references | | | District | char(20) | latin1_swedish_ci | NO | | | | select,insert,update,references | | | Population | int(11) | NULL | NO | | 0 | | select,insert,update,references | | +-------------+----------+-------------------+------+-----+---------+----------------+---------------------------------+---------+ 5 rows in set (0.00 sec)
使用 show columns from tableName from dbName 查看指定数据库下面指定表格的结构。
如下：
mysql> show columns from city from world; +-------------+----------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------+----------+------+-----+---------+----------------+ | ID | int(11) | NO | PRI | NULL | auto_increment | | Name | char(35) | NO | | | | | CountryCode | char(3) | NO | MUL | | | | District | char(20) | NO | | | | | Population | int(11) | NO | | 0 | | +-------------+----------+------+-----+---------+----------------+ 5 rows in set (0.00 sec)
