A brief discussion on MySQL drifting (4)

Before reading Code_Xiaosheng’s MySQL Drifting Notes IV, I hope that if you have time, you can briefly read MySQL Drifting Notes (1), MySQL Drifting Notes (2) and MySQL Drifting Notes (3)!

PS: The fourth section should be regarded as a small supplement to the database-related operations and the previously created database!

1) Create a database:
Use if exists to determine whether it already exists. If it does not exist, it will be created. If it already exists, it will not be created and no error will be reported. If it is not used, create it again. Databases with the same name will report an error!

Case: create database if not exists new08;

2) Display database:
show command, display the built database

Case: show databases;

You can see all the built databases;
If I want to fuzzy query the database starting with "new..", I can use the like keyword:

Case: show databases like ‘new%’

Notes:
01–% is a wildcard character, representing one or more characters;
02–_underscore is a wildcard character, representing one character;
03–When using the show command, remember that the following databases are in plural form. I saw a post on the Internet last time. A friend struggled with writing "s" for a long time. Ahem...

3) Select database
Syntax:

use +database 
Case: use new01;

A line 'Database changed' will appear ' Friendly reminder;

4) Delete the database
Use the drop command
Syntax:

drop  database +数据库名字； 
Case: drop database new01;

Pay attention to the if exists command;

Case：drop database  if exists new04;

The advantage of adding if exists is to avoid the new04 database not existing and then reporting an error message.

Before reading Code_Xiaosheng's MySQL Drifting Notes IV, I hope that if you have time, you can briefly take a look at MySQL Drifting Notes (1), MySQL Drifting Notes (2) and MySQL Drifting Notes (3)!

PS: The fourth section should be regarded as a small supplement to the related operations of the database and the previously created database!

1) Create a database:
Use if exists to determine whether it already exists. If it does not exist, it will be created. If it already exists, it will not be created and no error will be reported. If it is not used, create it again. Databases with the same name will report an error!

Case: create database if not exists new08;

2) Display database:
show command, display the built database

Case: show databases;

Yes See all the built databases;
If I want to fuzzy query the database starting with "new..", I can use the like keyword:

Case: show databases like ‘new%’

Notes:
01 –% is a wildcard character, representing one or more characters;
02–_Underscore is a wildcard character, representing one character;
03–When using the show command, remember that the following databases are in plural form. Last time I saw it online When I came to a post, a friend was struggling for a long time to write "s", cough...

3) Select database
syntax:

use +database 
Case: use new01;

will appear a line of 'Database changed' Tips;

4) Delete the database
Use the drop command
Syntax:

drop  database +数据库名字； 
Case: drop database new01;

Pay attention to the if exists command;

Case：drop database  if exists new04;

The advantage of adding if exists is to avoid the new04 database not existing and then reporting an error message,

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