MySQL database operation commands and mysql commands

MySQL database operation commands and mysql commands

Note: MySQL databases are case-insensitive.

1. Create a database:Create database Thinkgamer;

2. delete a database:Drop database Thinkgamer;

3. Select a database:Use Thinkgamer;

4. Create a data table:

Mysql> create table cyan

-> (
-> Student ID int (3) not null primary key,

-> Name char (3 );

-> Gender char (1) not null default 1
->) Engine = innodb;

Press enter. not null indicates that this field cannot be blank. primary key indicates that the primary key is set and default name is 1 by default.

5. delete a table:Drop table cyan;

6. add columns to the table:Alter table cyan add char (20 );

7. display information about the table:Describe cyan;

8. display the information of a column:Select student ID from cyan;

9. add information to the table:Insert cyan values ("111", "Thinkgamer", "female", "dance ");

10. Modify the information of a table row:

Mysql> update cyan
-> Set gender = "male", hobbies = "badminton"

-> Where student no. = 111;

Press enter.

1. Modify the information of multiple tables:

Mysql> update table_name1, table_name2
-> Set table_name1. Gender = "male", table_name2. Gender = "female"

-> Where table_name1.id = table_name2.id;

Press enter.

12. delete a row:Delete from cyan where student ID = 111;

13. remove a person with a gender:Delete from cyan where gender = female;

14. Delete multiple rows from multiple tables:

Mysql> delete table1, table2

-> From table1, table2, table3

-> Where table1.id = table2.id and table2.id = table3.id;

Press enter.

15. Clear table data:Truncate table cyan;

Note: once the data is cleared, it cannot be recovered.

Others:

Select user (); displays the current user.

Select @ version; displays the database version.

Show cyan status; displays the status of the currently used table

Show character set; displays the character sets supported by the database

Show variables like '% char %' view default Character Set

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