Shulou(Shulou.com)06/01 Report--

How does mysql modify the primary key? This problem may be often seen in our daily study or work. I hope you can gain a lot from this question. The following is the reference content that the editor brings to you, let's take a look at it!

Mysql modifies the primary key by first executing the [alter table table name drop primary key;] command to delete the primary key, and then executing the [alter table table name add primary key (id)] command to re-add the primary key.

Specific methods:

For example, to delete the original primary key constraint of the coal_3 table, execute the command:

Alter table coal_3 drop primary key

It should be noted that if the primary key is set to auto-increment, you need to remove the auto-increment first, and then delete the primary key.

Then add the primary key again, with the following command:

Alter table coal_3 add primary key (id) Thank you for your reading! After reading the above, do you have a general idea of how mysql modifies the primary key? I hope the content of the article will be helpful to all of you. If you want to know more about the relevant articles, you are welcome to follow the industry information channel.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.