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This article mainly tells you briefly what is the basic language of mysql. You can look up the relevant professional terms on the Internet or find some related books to supplement them. We will not dabble here. Let's go straight to the topic. I hope this article on what is the basic language of mysql can bring you some practical help.

MySQL is a relational database developed in the 1990s. MySQL5.0 adds support for advanced features such as views, database stored procedures, triggers, cloud server cursors, and distributed transaction protocols.

MySQL advantages: open source, free, cross-platform, high performance, more users

Weakness: poor conformance of SQL standards.

When facing an unfamiliar database, we usually need a way to interact with it, so SQL language is used.

SQL is an acronym for structured query (Structure Query Language). It is a database application language that uses relational models. Most relational database systems support SQL.

Relational database is a database based on relational model, which stores and processes data in the form of two-dimensional tables. Relational database is a database composed of multiple two-dimensional row and column tables that can be connected to each other.

Second, the classification of SQL language.

DDL statement: data definition language. Define different data segments, databases, tables, columns, indexes and other database objects. Common sentence keywords include create, drop, alter.

The creation of database

CREATE DATABASE database name

[CHARACTER SET 'utf8' COLLATE' utf8_general_ci'] set database character set and character set proofreading rules

CREATE DATABASE exam CHARACTER SET 'utf8' COLLATE' utf8_general_ci'

Toggle database:use database name

USE exam

Modification of database

Alter database exam character set utf8

Deletion of database

Drop database database name

Creation of tables

CREATE TABLE table name (attribute 1 data type [length] [constraint],.) [ENGINE=INNODB DEFAULT CHARSET=utf8]; (storage engine and character set) such as

Introduction to constraint data types

Added when ENGINE=INNODB DEFAULT CHARSET=utf8; creates a list, Chinese characters can emerge.

Modification of table

Alter table table name

Add field Alter table add column column name type

Add constraint Alter table table name alter column column name set default 'value'

Alter table table name add constraint primary key name primary key table name (primary key field)

Alter table table name add constraint foreign key name foreign key (foreign key field) references associated table name (associated field)

Modify field Alter table table name change original field name new field name data type [attribute]

Delete field alter table table name drop field name

Modify constraint alter table table name add constraint foreign key name foreign key (foreign key field) references associated table name (associated field)

Deletion of tables

Drop table table name

Insert the data of the table

Insert into table name (column 1, column 2,. ) values ('axioma1,)

Update the data of the table

Update table name set column name = update value [where update condition]

Deletion of table data

Delete from table name [where update condition]

DML operation refers to the operation of table records in the database, including insert (insert), update (update), delete (delete), query (select) of table records.

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