How can Mysql use commands to achieve hierarchical search help?

How can Mysql use commands to achieve hierarchical search help?

Preface

This article mainly introduced to you the Mysql use command classification to find help related content, this article sample branch version MariaDB-10.1.19 Based on msql, share for your reference to learn, below not much to say, let's take a look at the detailed introduction:

Query all help

If you want to know what mysql can do for us, run the following command:

? contents

Or set? It can also be replaced with help, and the effects are the same.

help contents

Results:

? It is equivalent to help in order to make it easier for us to use it all below ?, However, readers need to know that the same effect is true if we use help.

Explanations

English	Chinese	Description
Account Management	Account Management
Administration	Management
Compound Statements	Compound statement
Data Definition	Data Definition
Data Manipulation	Data Operations
Data Types	Data Type
Functions	Function	Generally, non-SQL standard commands are provided only by this product and the same series of products.
Functions and Modifiers for Use with GROUP	Grouping functions and modifiers
Geographic Features	Distributed features
Help Metadata	Metadata
Language Structure	Language Structure
Plugins	Plug-ins
Procedures	Stored Procedure
Storage Engines	Storage Engine
Table Maintenance	Table maintenance
Transactions	Transactions
User-Defined Functions	User-Defined Functions
Utility	Other help	I cannot understand the Chinese meaning here, but it is recommended for readers to execute it? Utility to see how it can help

Grade view help

Now we know what types of help can be searched. At this time, we can use question marks + spaces + specific names to be searched = case insensitive = for different projects.

For example, I want to find the supported data types

? data type

Effect

There are many data types. Generally, we may only use char varchar int boolean bit timestamp datetime float, and so on. However, there are still many unknown and rarely used data types, such: BIGINT, ENUM, BLOB, etc. In some cases, such as database optimization, if we need to learn more about a type of feature or want to know if there is a more suitable data type, can we use it all? Find the corresponding data type

For example

Now, we can know that BLOB is a data type that can hold 65535 bytes.

Based on this method, you can save Baidu's time in actual development and directly find the required help level by level.

Summary

The above is all the content of this article. I hope the content of this article will help you in your study or work. If you have any questions, please leave a message, thank you for your support.