Simple operation of MySQL database

Log in to the database ：mysql -u root -p Just enter the password .

Lists all databases that the current user can view ： mysql> SHOW DATABASES;

Create a file called test_db The database of ： mysql> CREATE DATABASE test_db;

Use LIKE clause , Check with test_db Exactly matched database ： mysql> SHOW DATABASES LIKE 'test_db';

Use LIKE clause , Check that the name contains test The database of ： mysql> SHOW DATABASES LIKE '%test%';

example ：

1. establish score surface

2. insert data

 

 3. Query all the information in the table

 4. check >=80 Points of

 5. Inquire about Out Good grades in all subjects >=80 Student name of

What you want is to display the name , Other information does not need to be displayed .

Continuous optimization ！

The name is repeated

 

Optimize again

Only one qualified name will be displayed .