规范的使用mysql语句使信息不至于很混乱，当然替换成小写也是可以做到一样的效果(不推荐)

mysql常用命令

• SELECT   VERSION();    显示服务器版本信息
• SELECT   NOW();             显示当前日期时间
• SELECT   USER();            显示当前登录用户

mysql语句规范

• 关键字和函数名必须全部大写
• 数据库名称、表名称、字段名称全部小写
• SQL语句必须已分号(;)结尾

数据库操作

IF EXISTS用于防止当数据库不存在时发生错误。

创建数据库、表

CREATE { DATABASE  | SCHEMA }  [ IF NOT EXISTS ] db_name [ DEFAULT ] CHARCTER SET [=] charset_name
CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name [(create_definition,...)] [table_options] [select_statement]

表改名

RENAME TABLE tbl_name TO new_tbl_name  [, tbl_name2 TO new_tbl_name2] ...

查看当前数据库、表、表结构

SHOW {  DATABASE  |  SCHEMA  }  [LINK 'pattern'  |   WHERE  expr]
SHOW [FULL] TABLES [FROM db_name] [LIKE 'pattern']
SHOW [FULL] COLUMNS FROM tbl_name [FROM db_name] [LIKE 'pattern']
DESC tbl_name

删除数据库

DROP {DATABASE | SCHEMA} [IF EXISTS] db_name

修改数据表

增加单列多列、删除单列、修改单列属性、修改单列属性及名称

ALTER TABLE tbl_name ADD [COLUMN] column_definition [FIRST | AFTER col_name ]
ALTER TABLE tbl_name ADD [COLUMN] (column_definition,...)
ALTER TABLE tbl_name DROP [COLUMN] col_name
ALTER TABLE tbl_name DROP INDEX index_name
ALTER TABLE tbl_name MODIFY [COLUMN] column_definition [FIRST | AFTER col_name]
ALTER TABLE tbl_name CHANGE [COLUMN] old_col_name column_definition [FIRST|AFTER col_name]

 增加记录

INSERT  [INTO] tbl_name [(col_name,...)] VALUES ({expr | DEFAULT},...),(...),...  [ ON DUPLICATE KEY UPDATE col_name=expr, ... ]

删除记录

DELETE [LOW_PRIORITY] [QUICK] [IGNORE] FROM tbl_name [WHERE where_definition] [ORDER BY ...] [LIMIT row_count]

更新记录

UPDATE [LOW_PRIORITY] [IGNORE] tbl_name SET col_name1=expr1 [, col_name2=expr2 ...] [WHERE where_definition] [ORDER BY ...] [LIMIT row_count]

 查找记录

SELECT select_expr FROM table_references [WHERE where_definition] [GROUP BY {col_name | expr | position}[ASC | DESC], ... [WITH ROLLUP]]

点击下载：mysql手册下载