Add @GeneratedValue on a later point, when data in table is already present-CodePudding

An entity which has ID but the data in corresponding table was added manually, for this reason @GeneratedValue annotation was never added. Now I need to create records in this table through code and want my ID to be auto-incremented. On adding @Id @GeneratedValue(strategy = GenerationType.AUTO) Integer id; The exception I get is:

java.sql.SQLException: Field 'id' doesn't have a default value

Is there a way to make this work?

CodePudding user response：

You need to change the column definition in the database to add a default value of "AUTO_INCREMENT".

For Mysql:

ALTER TABLE yourtable MODIFY COLUMN ID INT NOT NULL AUTO_INCREMENT;

I think you should also set the next AUTO_INCREMENT value for the table to the actual maximum value of the id 1:

ALTER TABLE yourtable AUTO_INCREMENT = new_value;