数据库操作_DDL_MySql入门_001
发布时间：2022-09-30 12:49:49 所属栏目：MySql教程 来源：
导读： -- 查看数据库
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performan
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performan
|
-- 查看数据库 mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | +--------------------+ 3 rows in set (0.00 sec) 一 创建 mysql> -- 创建数据库 mysql> CREATE DATABASE db1; Query OK, 1 row affected (0.01 sec) mysql> -- 创建的时候判断一下是否存在,再决定创建 mysql> CREATE DATABASE IF NOT EXISTS db2; Query OK, 1 row affected (0.00 sec) mysql> -- 创建的时候,指定字符集 mysql> create database db3 character set gbk; Query OK,1 row affected (0.00 sec) 二 查看 mysql> -- 2查看数据库 mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | db1 | | db2 | | db3 | | mysql | | performance_schema | +--------------------+ 6 rows in set (0.00 sec) mysql> -- 参看所有的数据库 mysql> -- 查看某个数据库的定义信息 mysql> show create database db1; +----------+--------------------------------------------------------------+ | Database | Create Database | +----------+--------------------------------------------------------------+ | db1 | CREATE DATABASE `db1` /*!40100 DEFAULT CHARACTER SET utf8 */ | +----------+--------------------------------------------------------------+ 1 row in set (0.00 sec) mysql> show create database db3; +----------+-------------------------------------------------------------+ | Database | Create Database | +----------+-------------------------------------------------------------+ | db3 | CREATE DATABASE `db3` /*!40100 DEFAULT CHARACTER SET gbk */ | +----------+-------------------------------------------------------------+ 1 row in set (0.00 sec) 3修改数据库 mysql> -- 1修改数据库默认的字符集 mysql> alter database db3 character set utf8; Query OKMySQL 删除数据库, 1 row affected (0.00 sec) mysql> show create database db3; +----------+--------------------------------------------------------------+ | Database | Create Database | +----------+--------------------------------------------------------------+ | db3 | CREATE DATABASE `db3` /*!40100 DEFAULT CHARACTER SET utf8 */ | +----------+--------------------------------------------------------------+ 1 row in set (0.00 sec) 4 删除数据库 mysql> -- 删除db2数据库 mysql> drop database db2; Query OK, 0 rows affected (0.45 sec) 5使用数据库 mysql> -- 查看正在使用的数据库 mysql> select database(); +------------+ | database() | +------------+ | NULL | +------------+ 1 row in set (0.00 sec) mysql> -- 使用或者称切换数据库 mysql> use db3; Database changed mysql> select database(); +------------+ | database() | +------------+ | db3 | +------------+ 1 row in set (0.00 sec) （编辑：均轻资讯网_我爱站长网） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |
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