How to Fix Hibernate's Unexpected Auto-Increment Field Inclusion in MySQL INSERT Statements?

Annotating MySQL Autoincrement Field with JPA Annotations

In JPA, the @GeneratedValue annotation is used to specify how the value of an auto-generated column should be generated. For MySQL, auto-increment columns are typically mapped with the GenerationType.IDENTITY strategy. However, if the generated SQL includes the auto-increment field, there may be a configuration mismatch.

In the given case, the Operator object has the following auto-increment field:

@Id
@GeneratedValue
private Long id;

This annotation should generate the following SQL:

insert 
into
    Operator
    (active, password, username) 
values
    (?, ?, ?)

However, the provided log shows that the SQL includes the id column:

Hibernate: insert into Operator (active, password, username, id) values (?, ?, ?, ?)

To resolve this, ensure that the following steps are followed:

1. Specify a MySQL Dialect: In the Hibernate configuration, specify a MySQL dialect, such as MySQL5InnoDBDialect or MySQL5Dialect.
2. Check the Table Definition: Verify that the table in question has an auto-increment column defined, as in the provided DDL:

CREATE TABLE `operator` ( 
`id` INT(10) NOT NULL AUTO_INCREMENT,
...

3. Review the Code: Double-check the Operator entity and ensure that it is annotated correctly with @GeneratedValue.
4. Clean Build and Debugging: Perform a clean build and check the build directory for any discrepancies. Additionally, inspect the logs for any suspicious activity.

If the issue persists, it may be necessary to explicitly specify the identity generation strategy:

@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;

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