查看mysql帮助信息

1. 查看DDL（数据定义）语句的具体指令

mysql> ? Data Definition;
You asked for help about help category: "Data Definition"
For more information, type 'help <item>', where <item> is one of the following
topics:
   ALTER DATABASE
   ALTER EVENT
   ALTER FUNCTION
   ALTER LOGFILE GROUP
   ALTER PROCEDURE
   ALTER SERVER
   ALTER TABLE
   ALTER TABLESPACE
   ALTER VIEW
   CONSTRAINT
   CREATE DATABASE
   CREATE EVENT
   CREATE FUNCTION
   CREATE INDEX
   CREATE LOGFILE GROUP
   CREATE PROCEDURE
   CREATE SERVER
   CREATE TABLE
   CREATE TABLESPACE
   CREATE TRIGGER
   CREATE VIEW
   DROP DATABASE
   DROP EVENT
   DROP FUNCTION
   DROP INDEX
   DROP PROCEDURE
   DROP SERVER
   DROP TABLE
   DROP TABLESPACE
   DROP TRIGGER
   DROP VIEW
   RENAME TABLE
   TRUNCATE TABLE

2. 查看DCL（授权控制）

mysql> ? Account Management
You asked for help about help category: "Account Management"
For more information, type 'help <item>', where <item> is one of the following
topics:
   ALTER USER
   CREATE USER
   DROP USER
   GRANT
   RENAME USER
   REVOKE
   SET PASSWORD

3. 查看DML（数据操控）帮助信息

mysql> ? Data Manipulation
You asked for help about help category: "Data Manipulation"
For more information, type 'help <item>', where <item> is one of the following
topics:
   CALL
   DELETE
   DO
   DUAL
   HANDLER
   INSERT
   INSERT DELAYED
   INSERT SELECT
   JOIN
   LOAD DATA
   LOAD XML
   REPLACE
   SELECT
   UNION
   UPDATE