Automatic database growth

Automatic growth

• Concept ： If a column is numeric , Use auto_increment Can be used to complete the automatic growth of value
• Realization ： When creating a table , Add primary key constraint , And complete the self growth of the primary key

CREATE TABLE stu(
	id INT PRIMARY KEY AUTO_INCREMENT
);

Add autogrow

ALTER TABLE stu MODIFY id AUTO_INCREMENT

• Be careful ： Automatic growth is only related to the immediately preceding value
• Delete auto growth

ALTER TABLE stu MODIFY id INT;