An important term in MySQL -- CRUD

       mysql Database operation , It mainly performs a series of operations on the files in the database , abbreviation CRUD, The following is a list of commonly used CRUD Instructions

C：create  establish

        Create database ：create database  Library name

        Create table ： create table Table name （ Field     attribute .....）

        Create foreign keys ：alter table The name of this table constraint Foreign key name foreign key Fields in this table references  Table name （ Field ）;

        Create index ：create index  Index name   on  Table name （ Field ）

R ：retrive check （ retrieval ）

        Check all databases ：show databases;

        Check the number of tables in the database ：show tables;

        Field format in lookup table ： desc  Library name

        Look up the complete format of the fields in the table ：show full fields from Table name

        Look up the field definition format in the table ： show create table Table name

        Look at the data in the table   select * from Table name

U:  update  modify , to update

          Modify the data in the table ：update  table Table name   set    Field = value    where  Conditions

          Add fields    alter table Table name   add Field   attribute ;

          Modifying the properties of fields in a table ： alter table Table name modify Field name   attribute

          Modify the names and attributes of fields in the table ： alter table Table name    change Old field name , new field name   attribute

D：delete

          Delete database ： drop database  Library name

          Delete table ： drop table Table name

          Delete data ：delete table Table name   where Conditions

                           truncat  table Table name

          Delete foreign key ：alter table Table name drop foreign key Foreign key name

          Delete index ：alter table  Table name   drop index Index name