MySQL帮助文档的使用
帮助文档使用
在 MySQL 使用过程中,可能经常会遇到以下问题:
- 某个操作语法忘记了,需要快速查找。
- 当前版本上,某个字段类型我们想快速知道它的取值范围?
- 当前版本上,都支持哪些函数?希望有例子能快速入门。
- 当前版本上,是否支持某个功能?
对于上面列出的各种问题,我们可能想到的办法是查找 MySQL 的文档。不错,这些问题在 MySQL 官方文档中都可以很清楚地查到,但是却要耗费大量的时间和精力。 所以对于以上问题,最好的解决办法是使用 MySQL 安装后自带的帮助文档,这样在遇到问 题时就可以方便快捷地进行查询。
按照层次看帮助
如果不知道帮助能够提供些什么,可以用“?contents”命令来显示所有可供查询的的分类, 如下例所示:
mysql> ? contents
You asked for help about help category: "Contents"
For more information, type 'help <item>', where <item> 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
Language Structure
Plugins
Procedures
Storage Engines
Table Maintenance
Transactions
User-Defined Functions
Utility
对于列出的分类,可以使用“? 类别名称”的方式针对用户感兴趣的内容做进一步的查看。 例如,想看看 MySQL 中都支持哪些数据类型,可以执行“? data types”命令:
mysql> ? data types
You asked for help about help category: "Data Types"
For more information, type 'help <item>', where <item> is one of the following
topics:
AUTO_INCREMENT
BIGINT
BINARY
BIT
BLOB
BLOB DATA TYPE
BOOLEAN
CHAR
CHAR BYTE
DATE
DATETIME
DEC
DECIMAL
DOUBLE
DOUBLE PRECISION
ENUM
FLOAT
INT
INTEGER
LONGBLOB
LONGTEXT
MEDIUMBLOB
MEDIUMINT
MEDIUMTEXT
SET DATA TYPE
SMALLINT
TEXT
TIME
TIMESTAMP
TINYBLOB
TINYINT
TINYTEXT
VARBINARY
VARCHAR
YEAR DATA TYPE上面列出的此版本支持的所有数据类型,如果想知道int类型的具体介绍,也可以使用上忙的方法,做进一步的查看:
mysql> ? int
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. URL: http://dev.mysql.com/doc/refman/5.6/en/numeric-type-overview.html
帮助文档中显示了 int 类型的详细描述。通过这种“? 类别名称”的方式,就可以一层层 地往下查找用户所关心的主题内容。
快速查阅帮助
在实际应用当中,如果需要快速查阅某项语法时,可以使用关键字进行快速查询。例如,想 知道 show 命令都能看些什么东西,可以用如下命令:
mysql> ? show
Name: 'SHOW'
Description:
SHOW has many forms that provide information about databases, tables,
columns, or status information about the server. This section describes
those following: SHOW AUTHORS
SHOW {BINARY | MASTER} LOGS
SHOW BINLOG EVENTS [IN 'log_name'] [FROM pos] [LIMIT [offset,] row_count]
SHOW CHARACTER SET [like_or_where]
SHOW COLLATION [like_or_where]
SHOW [FULL] COLUMNS FROM tbl_name [FROM db_name] [like_or_where]
SHOW CONTRIBUTORS
SHOW CREATE DATABASE db_name
SHOW CREATE EVENT event_name
SHOW CREATE FUNCTION func_name
SHOW CREATE PROCEDURE proc_name
SHOW CREATE TABLE tbl_name
SHOW CREATE TRIGGER trigger_name
SHOW CREATE VIEW view_name
SHOW DATABASES [like_or_where]
SHOW ENGINE engine_name {STATUS | MUTEX}
SHOW [STORAGE] ENGINES
SHOW ERRORS [LIMIT [offset,] row_count]
SHOW EVENTS
SHOW FUNCTION CODE func_name
SHOW FUNCTION STATUS [like_or_where]
SHOW GRANTS FOR user
SHOW INDEX FROM tbl_name [FROM db_name]
SHOW MASTER STATUS
SHOW OPEN TABLES [FROM db_name] [like_or_where]
SHOW PLUGINS
SHOW PROCEDURE CODE proc_name
SHOW PROCEDURE STATUS [like_or_where]
SHOW PRIVILEGES
SHOW [FULL] PROCESSLIST
SHOW PROFILE [types] [FOR QUERY n] [OFFSET n] [LIMIT n]
SHOW PROFILES
SHOW RELAYLOG EVENTS [IN 'log_name'] [FROM pos] [LIMIT [offset,] row_count]
SHOW SLAVE HOSTS
SHOW SLAVE STATUS
SHOW [GLOBAL | SESSION] STATUS [like_or_where]
SHOW TABLE STATUS [FROM db_name] [like_or_where]
SHOW [FULL] TABLES [FROM db_name] [like_or_where]
SHOW TRIGGERS [FROM db_name] [like_or_where]
SHOW [GLOBAL | SESSION] VARIABLES [like_or_where]
SHOW WARNINGS [LIMIT [offset,] row_count] like_or_where:
LIKE 'pattern'
| WHERE expr If the syntax for a given SHOW statement includes a LIKE 'pattern'
part, 'pattern' is a string that can contain the SQL % and _ wildcard
characters. The pattern is useful for restricting statement output to
matching values. Several SHOW statements also accept a WHERE clause that provides more
flexibility in specifying which rows to display. See
http://dev.mysql.com/doc/refman/5.6/en/extended-show.html. URL: http://dev.mysql.com/doc/refman/5.6/en/show.html
例如,如果想参看CREATE TABLE 的语法,可以使用以下命令:
mysql> ? 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]
[IGNORE | REPLACE]
[AS] query_expression CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name
{ LIKE old_tbl_name | (LIKE old_tbl_name) } create_definition:
col_name column_definition
| [CONSTRAINT [symbol]] PRIMARY KEY [index_type] (index_col_name,...)
[index_option] ...
| {INDEX|KEY} [index_name] [index_type] (index_col_name,...)
[index_option] ...
| [CONSTRAINT [symbol]] UNIQUE [INDEX|KEY]
[index_name] [index_type] (index_col_name,...)
[index_option] ...
| {FULLTEXT|SPATIAL} [INDEX|KEY] [index_name] (index_col_name,...)
[index_option] ...
| [CONSTRAINT [symbol]] FOREIGN KEY
[index_name] (index_col_name,...) reference_definition
| CHECK (expr) column_definition:
data_type [NOT NULL | NULL] [DEFAULT default_value]
[AUTO_INCREMENT] [UNIQUE [KEY] | [PRIMARY] KEY]
[COMMENT 'string']
[COLUMN_FORMAT {FIXED|DYNAMIC|DEFAULT}]
[STORAGE {DISK|MEMORY|DEFAULT}]
[reference_definition] data_type:
BIT[(length)]
| TINYINT[(length)] [UNSIGNED] [ZEROFILL]
| SMALLINT[(length)] [UNSIGNED] [ZEROFILL]
| MEDIUMINT[(length)] [UNSIGNED] [ZEROFILL]
| INT[(length)] [UNSIGNED] [ZEROFILL]
| INTEGER[(length)] [UNSIGNED] [ZEROFILL]
| BIGINT[(length)] [UNSIGNED] [ZEROFILL]
| REAL[(length,decimals)] [UNSIGNED] [ZEROFILL]
| DOUBLE[(length,decimals)] [UNSIGNED] [ZEROFILL]
| FLOAT[(length,decimals)] [UNSIGNED] [ZEROFILL]
| DECIMAL[(length[,decimals])] [UNSIGNED] [ZEROFILL]
| NUMERIC[(length[,decimals])] [UNSIGNED] [ZEROFILL]
| DATE
| TIME[(fsp)]
| TIMESTAMP[(fsp)]
| DATETIME[(fsp)]
| YEAR
| CHAR[(length)] [BINARY]
[CHARACTER SET charset_name] [COLLATE collation_name]
| VARCHAR(length) [BINARY]
[CHARACTER SET charset_name] [COLLATE collation_name]
| BINARY[(length)]
| VARBINARY(length)
| TINYBLOB
| BLOB
| MEDIUMBLOB
| LONGBLOB
| TINYTEXT [BINARY]
[CHARACTER SET charset_name] [COLLATE collation_name]
| TEXT [BINARY]
[CHARACTER SET charset_name] [COLLATE collation_name]
| MEDIUMTEXT [BINARY]
[CHARACTER SET charset_name] [COLLATE collation_name]
| LONGTEXT [BINARY]
[CHARACTER SET charset_name] [COLLATE collation_name]
| ENUM(value1,value2,value3,...)
[CHARACTER SET charset_name] [COLLATE collation_name]
| SET(value1,value2,value3,...)
[CHARACTER SET charset_name] [COLLATE collation_name]
| spatial_type index_col_name:
col_name [(length)] [ASC | DESC] index_type:
USING {BTREE | HASH} index_option:
KEY_BLOCK_SIZE [=] value
| index_type
| WITH PARSER parser_name
| COMMENT 'string' reference_definition:
REFERENCES tbl_name (index_col_name,...)
[MATCH FULL | MATCH PARTIAL | MATCH SIMPLE]
[ON DELETE reference_option]
[ON UPDATE reference_option] reference_option:
RESTRICT | CASCADE | SET NULL | NO ACTION | SET DEFAULT table_options:
table_option [[,] table_option] ... table_option:
ENGINE [=] engine_name
| AUTO_INCREMENT [=] value
| AVG_ROW_LENGTH [=] value
| [DEFAULT] CHARACTER SET [=] charset_name
| CHECKSUM [=] {0 | 1}
| [DEFAULT] COLLATE [=] collation_name
| COMMENT [=] 'string'
| CONNECTION [=] 'connect_string'
| DATA DIRECTORY [=] 'absolute path to directory'
| DELAY_KEY_WRITE [=] {0 | 1}
| INDEX DIRECTORY [=] 'absolute path to directory'
| INSERT_METHOD [=] { NO | FIRST | LAST }
| KEY_BLOCK_SIZE [=] value
| MAX_ROWS [=] value
| MIN_ROWS [=] value
| PACK_KEYS [=] {0 | 1 | DEFAULT}
| PASSWORD [=] 'string'
| ROW_FORMAT [=] {DEFAULT|DYNAMIC|FIXED|COMPRESSED|REDUNDANT|COMPACT}
| STATS_AUTO_RECALC [=] {DEFAULT|0|1}
| STATS_PERSISTENT [=] {DEFAULT|0|1}
| STATS_SAMPLE_PAGES [=] value
| TABLESPACE tablespace_name [STORAGE {DISK|MEMORY|DEFAULT}]
| UNION [=] (tbl_name[,tbl_name]...) partition_options:
PARTITION BY
{ [LINEAR] HASH(expr)
| [LINEAR] KEY [ALGORITHM={1|2}] (column_list)
| RANGE{(expr) | COLUMNS(column_list)}
| LIST{(expr) | COLUMNS(column_list)} }
[PARTITIONS num]
[SUBPARTITION BY
{ [LINEAR] HASH(expr)
| [LINEAR] KEY [ALGORITHM={1|2}] (column_list) }
[SUBPARTITIONS num]
]
[(partition_definition [, partition_definition] ...)] partition_definition:
PARTITION partition_name
[VALUES
{LESS THAN {(expr | value_list) | MAXVALUE}
|
IN (value_list)}]
[[STORAGE] ENGINE [=] engine_name]
[COMMENT [=] 'comment_text' ]
[DATA DIRECTORY [=] 'data_dir']
[INDEX DIRECTORY [=] 'index_dir']
[MAX_ROWS [=] max_number_of_rows]
[MIN_ROWS [=] min_number_of_rows]
[TABLESPACE [=] tablespace_name]
[NODEGROUP [=] node_group_id]
[(subpartition_definition [, subpartition_definition] ...)] subpartition_definition:
SUBPARTITION logical_name
[[STORAGE] ENGINE [=] engine_name]
[COMMENT [=] 'comment_text' ]
[DATA DIRECTORY [=] 'data_dir']
[INDEX DIRECTORY [=] 'index_dir']
[MAX_ROWS [=] max_number_of_rows]
[MIN_ROWS [=] min_number_of_rows]
[TABLESPACE [=] tablespace_name]
[NODEGROUP [=] node_group_id] query_expression:
SELECT ... (Some valid select or union statement) CREATE TABLE creates a table with the given name. You must have the
CREATE privilege for the table. By default, tables are created in the default database, using the
InnoDB storage engine. An error occurs if the table exists, if there is
no default database, or if the database does not exist. For information about the physical representation of a table, see
http://dev.mysql.com/doc/refman/5.6/en/create-table-files.html. URL: http://dev.mysql.com/doc/refman/5.6/en/create-table.html
常用的网络资源
http://dev.mysql.com/downloads/是MySQL 的官方网站,可以下载到各个版本的 MySQL 以及 相关客户端开发工具等。
http://dev.mysql.com/doc/提供了目前最权威的 MySQL 数据库及工具的在线手册。
http://bugs.mysql.com/这里可以查看到MySQL 已经发布的bug 列表,或者向MySQL提交 bug 报告。
http://www.mysql.com/news-and-events/newsletter/通常会发布各种关于MySQL的最新消息
小结:
本章简单地介绍了 SQL 语句的基本分类 DML/DDL/DCL,并对每一种分类下的常用 SQL 的用 法进行了举例说明。MySQL 在标准 SQL 的基础上进行了很多扩展,本章对常用的一些语法 做了简单介绍,更详细的说明,读者可以参考 MySQL 的帮助或者官方文档。在本章的最后, 还介绍了用户应如何使用 MySQL 中的帮助文档,以便快速查找各种语法定义
MySQL帮助文档的使用的更多相关文章
- 高效查看MySQL帮助文档的方法
在mysql的使用过程中, 可能经常会遇到以下问题: 某个操作语法忘记了, 如何快速查找? 如何快速知道当前版本上某个字段类型的取值范围? 当前版本都支持哪些函数?希望有例子说明.. 当前版本是否支持 ...
- 高效查看MySQL帮助文档的方法 (转)
在mysql的使用过程中, 可能经常会遇到以下问题: 某个操作语法忘记了, 如何快速查找? 如何快速知道当前版本上某个字段类型的取值范围? 当前版本都支持哪些函数?希望有例子说明.. 当前版本是否支持 ...
- [转载]linux+nginx+python+mysql安装文档
原文地址:linux+nginx+python+mysql安装文档作者:oracletom # 开发包(如果centos没有安装数据库服务,那么要安装下面的mysql开发包) MySQL-devel- ...
- 基于Mybatis的Mysql数据库文档生成工具,支持生成docx(原创)
今天不写android--也写写数据库相关的东西 -------------------- 今日老夫闲来无事,设计了一款数据库文档生成工具 眼下仅仅支持mysql 主要是生成docx的 下载链接:下载 ...
- MySQL相关文档索引
MySQL的新功能5.7 https://dev.mysql.com/doc/refman/5.7/en/mysql-nutshell.html MySQL5.7安装 http://note.youd ...
- MySQL安装指导文档
MySQL 是最流行的关系型数据库管理系统,可以在本地搭建一个mysql的环境,便于学习. windows7/windows10 5.7.26 安装mysql前环境准备工作 1) 要有Net fram ...
- 使用Sed抽取MySQL安装文档的目录及行号
sed -nr -e '/^2.|^shell/=' -e '/^2.|^shell/p' INSTALL-SOURCE |awk '{if (NR%2==1) x=$1; else printf ...
- mysql插入文本文档及读取
1.把本地的一个文件插入到数据库中,数据库字段用text保存 public static void main(String[] args) { PropKit.use(“pro.txt”);Druid ...
- mysql设置文档快捷写
select distinct column_name,column_comment,column_type from information_schema.columns where table_n ...
随机推荐
- HashMap遍历,取出key和value
HashMap的遍历有两种常用的方法,那就是使用keyset及entryset来进行遍历,在用keySet(key)取value时候,需要key 第一种: Map map = new HashMap( ...
- 基于SILVACO ATLAS的a-IGZO薄膜晶体管二维器件仿真(08)
进展比较慢啊... 根据江南大学硕士论文IGZO/IZO双有源层薄膜晶体管特性的模拟研究: 其中, gCBa:类受主导带尾态 gVBd:类施主价带尾态 gGd:类施主氧空位态 NDeep:价带尾深施主 ...
- C/C++中size_t潜在的问题
在C++中,利用数组下标访问数组元素时,常常将下标类型定义为size_t类型,因为正常来说,数组的下标就是size_t类型.例如这样: for (size_t i = 0; i < contai ...
- VS2019 还原Resharper菜单位置
方法: 第一步: Tools -> Customize -> Extensions Menu tab, uncheck Resharper 工具->自定义->扩展菜单-> ...
- 干货 | C#开发的电影售票系统
01 介绍 一个有会员制的电影院购票系统.具有会员注册功能,可区分会员和散客两种身份,实现会员及折扣管理.购票具有挑选电影场次,选择座位和查看电影信息等功能. 查看电影详情.获取排片信息. 选择场次座 ...
- 探讨 Git 代码托管平台的若干问题
关于 Git 版本控制软件种类繁多,维基百科收录的最早的版本控制系统是 1972 年贝尔实验室开发的 Source Code Control System.1986 年 Concurrent Vers ...
- pillow 初级用法
# 转载至:https://www.cnblogs.com/apexchu/p/4231041.html Image类 Pillow中最重要的类就是Image,该类存在于同名的模块中.可以通过以下几种 ...
- PyQt5剪切板操作
1.使用剪切板import sys,mathfrom PyQt5.QtWidgets import *from PyQt5.QtGui import *from PyQt5.QtCore import ...
- 以太坊执行miner.start返回null终极解决方案
参考博文:https://blog.csdn.net/wo541075754/article/details/79260040
- CRS-1硬件维护
一.CRS-1硬件介绍CRS-1 路由器是Cisco 推出的新的大容量骨干路由器,是一个支持多机箱扩展的路由系统.其设计容量可以扩展至72 个线卡机箱.8 个矩阵机箱,总交换容量达到92Tbps,具有 ...