在新版本的centos7中默认的yum安装mysql，已经备替换为MariaDB，两者的sql命令和相关操作完全贴合，下面是两种安装方法：
centos7:
内核版本：3.10.0-514.26.2.el7.x86_64
安装MariaDB:
yum install mariadb mariadb-server
启动mariadb服务：
systemctl start mariadb
连接数据库：
mysql -uroot -p
首次默认root密码为空，直接回车进入数据库。
使用mysql_secure_installation进行，设置root密码，删除测试数据库，匿名用户等操作。
cent7以下版本yum安装mysql：
yum install mysql mysql-server mysql-devel
启动服务：
service start mysqld
连接数据库：
mysql -uroot -p
首次默认root密码为空，直接回车进入数据库。
使用mysql_secure_installation进行，设置root密码，删除测试数据库，匿名用户等操作。
常见mysql语句说明：
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语句
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语法
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AND / OR
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SELECT column_name(s) FROM table_name WHERE condition AND|OR condition
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ALTER TABLE (add column)
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ALTER TABLE table_name ADD column_name datatype
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ALTER TABLE (drop column)
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ALTER TABLE table_name DROP COLUMN column_name
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AS (alias for column)
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SELECT column_name AS column_alias FROM table_name
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AS (alias for table)
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SELECT column_name FROM table_name AS table_alias
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BETWEEN
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SELECT column_name(s) FROM table_name WHERE column_name BETWEEN value1 AND value2
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CREATE DATABASE
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CREATE DATABASE database_name
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CREATE INDEX
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CREATE INDEX index_name ON table_name (column_name)
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CREATE TABLE
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CREATE TABLE table_name
(
column_name1 data_type,
column_name2 data_type,
.......
)
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CREATE UNIQUE INDEX
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CREATE UNIQUE INDEX index_name ON table_name (column_name)
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CREATE VIEW
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CREATE VIEW view_name AS SELECT column_name(s) FROM table_name WHERE condition
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DELETE FROM
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DELETE FROM table_name (
Note:
Deletes the entire table!!)
or
DELETE FROM table_name WHERE condition
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DROP DATABASE
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DROP DATABASE database_name
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DROP INDEX
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DROP INDEX table_name.index_name
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DROP TABLE
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DROP TABLE table_name
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GROUP BY
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SELECT column_name1,SUM(column_name2) FROM table_name GROUP BY column_name1
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HAVING
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SELECT column_name1,SUM(column_name2) FROM table_name GROUP BY column_name1 HAVING SUM(column_name2) condition value
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IN
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SELECT column_name(s) FROM table_name WHERE column_name IN (value1,value2,..)
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INSERT INTO
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INSERT INTO table_name VALUES (value1, value2,....)
or
INSERT INTO table_name (column_name1, column_name2,...) VALUES (value1, value2,....)
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LIKE
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SELECT column_name(s) FROM table_name WHERE column_name LIKE pattern
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ORDER BY
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SELECT column_name(s) FROM table_name ORDER BY column_name [ASC|DESC]
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SELECT
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SELECT column_name(s) FROM table_name
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SELECT *
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SELECT * FROM table_name
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SELECT DISTINCT
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SELECT DISTINCT column_name(s) FROM table_name
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SELECT INTO
(used to create backup copies of tables)
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SELECT * INTO new_table_name FROM original_table_name
or
SELECT column_name(s) INTO new_table_name FROM original_table_name
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TRUNCATE TABLE
(deletes only the data inside the table)
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TRUNCATE TABLE table_name
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UPDATE
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UPDATE table_name SET column_name=new_value [, column_name=new_value] WHERE column_name=some_value
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WHERE
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SELECT column_name(s) FROM table_name WHERE condition
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