Linux-mysql basic instructions-Adding and deleting changes

Common directives

instruction function	Instructions
View/Query	Show,select,desc
Create	Create
Delete	Drop,delete,truncate
Toggle/Enter	Use
Add a record	Insert

View the list of databases

show databases;

View current database The user logged in

Select User ();

See which tables are in the current database

Show tables;

To view the encoding type of the test database

Show create DATABASE test;

View the type of test table

Show create TABLE test;

View the definition information for the test table

DESC test;

Create a database

Create Database db1;

Create a database of type UTF8MB4

Create DATABASE DB2 DEFAULT CHARACTER SET UTF8MB4;

Create a table

CREATE TABLE students (ID int UNSIGNED not NULL PRIMARY key,name VARCHAR (a) not null,age tinyint UNSIGNED);

Add record for EMP table (with Id,name,sex,age field)

INSERT into EMP (id,name,sex,age) VALUES (1, ' xiaoming ', ' m ', 30);

Modify the contents of the EMP table (number of fields in the first few lines)

Update emp set age=18 where id=4;

Deleting a database

Drop database db1;

Delete Test table

DROP TABLE Test

Delete records in an EMP table

Delete from emp where name= ' Lvdou ';

Delete EMP entire table record

Delete from EMP;

Note: This command is slow to delete tens of thousands of records (because he logs, you can use the log to restore)

TRUNCATE TABLE emp; This command deletes tens of thousands of records, particularly quickly.

Because he doesn't record logs.

Empty the EMP table

TRUNCATE TABLE EMP;

Bulk Execute SQL Program

MySQL < Hellodb_innodb.sql

Note: You can also view the database without entering the database

Mysql-e ' Show databases '

Linux-mysql basic instructions-Adding and deleting changes