What is the statement to delete primary key in mysql

In mysql, the statement to delete the primary key is "Alter table tb drop primary key;"; the Alter table statement is used to modify the structure of the table, and drop is used to indicate deletion. If the columns in the table have dynamic growth attributes , you need to delete the auto-increment first before you can delete the primary key.

The operating environment of this tutorial: windows10 system, mysql8.0.22 version, Dell G3 computer.

What is the statement to delete the primary key in mysql

1) If the primary key id is not automatically incremented

The syntax for deleting the primary key is as follows:

Alter table tb drop primary key;//删除主建

##(2) If the primary key id is automatically incremented

The syntax for deleting a primary key is as follows:

Alter table tb change id id int(10);//删除自增长
Alter table tb drop primary key;//删除主建

Extended knowledge:

Add a primary key

(1) If the primary key id is not automatically incremented

Alter table tb add primary key(id);

(2) If the primary key id is automatically incremented

Alter table tb add primary key(id);
Alter table tb change id id int(10) not null auto_increment;

Recommended learning:

mysql video tutorial

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