#查看庫下面有多少張表. mysql> show tables; +----------------+ | Tables_in_test | +----------------+ | boy | | boy2 | | boy3 | | course | | pj | | sc | | sc2 | | stage | | student | +----------------+ 9 rows in set (0.00 sec) #刪除視圖 mysql> drop view pj; Query OK, 0 rows affected (0.00 sec) #刪除表 mysql> drop tables sc; Query OK, 0 rows affected (0.02 sec) #查看錶結構信息 mysql> desc boy; +--------+--------------+------+-----+------------+-------+ | Field | Type | Null | Key | Default | Extra | +--------+--------------+------+-----+------------+-------+ | hid | int(11) | NO | | NULL | | | bname | varchar(100) | NO | | NULL | | | birth | date | NO | | 0000-00-00 | | | weight | smallint(6) | YES | | NULL | | +--------+--------------+------+-----+------------+-------+ 4 rows in set (0.00 sec) #查看建表的過程、語句. mysql> show create table boy; +-------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table | +-------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | boy | CREATE TABLE `boy` ( `hid` int(11) NOT NULL, `bname` varchar(100) NOT NULL, `birth` date NOT NULL DEFAULT '0000-00-00', `weight` smallint(6) DEFAULT NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8 | +-------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec) #查看視圖建表過程(table/view都可以) mysql> show create table stage; +-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+ | View | Create View | character_set_client | collation_connection | +-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+ | stage | CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `stage` AS select `student`.`SNAME` AS `sname`,`student`.`AGE` AS `age` from `student` | utf8 | utf8_general_ci | +-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+ 1 row in set (0.00 sec) mysql> show create view stage; +-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+ | View | Create View | character_set_client | collation_connection | +-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+ | stage | CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `stage` AS select `student`.`SNAME` AS `sname`,`student`.`AGE` AS `age` from `student` | utf8 | utf8_general_ci | +-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+ 1 row in set (0.00 sec) #查看錶的信息和過程(所有表). mysql> show table status \G; *************************** 1. row *************************** Name: boy Engine: InnoDB Version: 10 Row_format: Compact Rows: 4 Avg_row_length: 4096 Data_length: 16384 Max_data_length: 0 Index_length: 0 Data_free: 0 Auto_increment: NULL Create_time: 2019-01-29 00:33:46 Update_time: NULL Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: #單獨的查看某張表的狀態、信息. mysql> show table status where name="student" \G; *************************** 1. row *************************** Name: student Engine: InnoDB Version: 10 Row_format: Compact Rows: 4 Avg_row_length: 4096 Data_length: 16384 Max_data_length: 0 Index_length: 0 Data_free: 0 Auto_increment: NULL Create_time: 2018-09-21 00:55:30 Update_time: NULL Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: 1 row in set (0.00 sec) ERROR: No query specified 清空表數據truncate和delete的區別? 使用delete對錶中的數據進行操作: #創建t2表 mysql> create table t2 ( id int primary key auto_increment ); Query OK, 0 rows affected (0.02 sec) mysql> select * from t2; Empty set (0.00 sec) #插入兩行數據. mysql> insert into t2 values (null); Query OK, 1 row affected (0.01 sec) mysql> insert into t2 values (null); Query OK, 1 row affected (0.01 sec) mysql> select * from t2; +----+ | id | +----+ | 1 | | 2 | +----+ 2 rows in set (0.00 sec) #delete其中的一條數據. mysql> delete from t2 where id="2"; Query OK, 1 row affected (0.00 sec) #再次插入數據. mysql> insert into t2 values (null); Query OK, 1 row affected (0.01 sec) #發現插入的id從3開始,繼續原數據的id增長. mysql> select * from t2; +----+ | id | +----+ | 1 | | 3 | +----+ 2 rows in set (0.00 sec) 使用truncate對錶中的數據進行操作: #表中的數據清空. mysql> truncate table t2; Query OK, 0 rows affected (0.02 sec) #插入數據 mysql> insert into t2 values (null); Query OK, 1 row affected (0.01 sec) #發現表的id從1開始. mysql> select * from t2; +----+ | id | +----+ | 1 | +----+ 1 row in set (0.00 sec) 注意:truncate操作其實相當與對錶進行了drop tables---create table操作.
mysql常用表管理語句
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