MySQL之帮助的使用

果果、

　　在MySQL中帮助的使用主要有以下两个方面：
　　1 按层次查找帮助：?|help + 类别名称
　　mysql> ? contents;                #有哪些分类
　　You asked for help about help category: "Contents"
　　For more information, type 'help ', where  is one of the following
　　categories:
　　Account Management
　　Administration
　　Compound Statements
　　Data Definition
　　Data Manipulation
　　Data Types
　　Functions
　　Functions and Modifiers for Use with GROUP BY
　　Geographic Features
　　Help Metadata
　　mysql> ? data types                #查看数据有哪些类型
　　You asked for help about help category: "Data Types"
　　For more information, type 'help ', where  is one of the following
　　topics:
　　AUTO_INCREMENT
　　BIGINT
　　BINARY
　　BIT
　　BLOB
　　BLOB DATA TYPE
　　BOOLEAN
　　CHAR
　　CHAR BYTE
　　DATE
　　DATETIME
　　DEC
　　DECIMAL
　　mysql> help int;                    #关于数据类型的说明
　　Name: 'INT'
　　Description:
　　INT[(M)] [UNSIGNED] [ZEROFILL]
　　A normal-size integer. The signed range is -2147483648 to 2147483647.
　　The unsigned range is 0 to 4294967295.
　　2 快速查阅帮助
　　mysql> ? create database;
　　Name: 'CREATE DATABASE'
　　Description:
　　Syntax:
　　CREATE {DATABASE | SCHEMA} [IF NOT EXISTS] db_name
　　[create_specification] ...
　　create_specification:
　　[DEFAULT] CHARACTER SET [=] charset_name
　　| [DEFAULT] COLLATE [=] collation_name
　　CREATE DATABASE creates a database with the given name. To use this
　　statement, you need the CREATE privilege for the database. CREATE
　　SCHEMA is a synonym for CREATE DATABASE.
　　......
　　mysql> help create table;
　　Name: 'CREATE TABLE'
　　Description:
　　Syntax:
　　CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name
　　(create_definition,...)
　　[table_options]
　　[partition_options]
　　CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name
　　[(create_definition,...)]
　　[table_options]
　　[partition_options]
　　select_statement
　　CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name
　　{ LIKE old_tbl_name | (LIKE old_tbl_name) }
　　......