mysql中创建表删除表及表查询

mysql中创建表

创建mysql表的sql语法

CREATE TABLE table_name (column_name column_type);

mysql中创建表示例

mysql> create table t1(    -> id1 float(5,2) default null,    -> id2 double(5,2) default null,    -> id3 decimal(5,2) default null);Query OK, 0 rows affected (0.80 sec)

mysql中删除表

mysql中删除表的sql语法

DROP TABLE table_name ;

mysql中删除表示例

[root@localhost ~]# mysql -u root -pEnter password: Welcome to the MySQL monitor.  Commands end with ; or \g.Your MySQL connection id is 15Server version: 5.7.18 MySQL Community Server (GPL)Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> use mysqlReading table information for completion of table and column namesYou can turn off this feature to get a quicker startup with -ADatabase changedmysql> drop table emp;Query OK, 0 rows affected (0.34 sec)mysql> 

mysql插入表及表查询

mysql> create table t1(    -> id1 float(5,2) default null,    -> id2 double(5,2) default null,    -> id3 decimal(5,2) default null);Query OK, 0 rows affected (0.98 sec)mysql> insert into t1 values(1.23,1.23,1.23);Query OK, 1 row affected (0.08 sec)mysql> insert into t1 values(1.243,1.243,1.243);Query OK, 1 row affected, 1 warning (0.27 sec)mysql> insert into t1 values(1.2453,1.2453,1.2453);Query OK, 1 row affected, 1 warning (0.08 sec)mysql> select * from t1;+------+------+------+| id1  | id2  | id3  |+------+------+------+| 1.23 | 1.23 | 1.23 || 1.24 | 1.24 | 1.24 || 1.25 | 1.25 | 1.25 |+------+------+------+3 rows in set (0.00 sec)mysql>