Hibernate in caused By:java.sql.SQLException:Field ' address_id ' doesn ' t has a default value

In learning hibernate, I believe many people have met:

Exception in thread ' main ' org.hibernate.exception.GenericJDBCException:could not execute statement
caused By:java.sql.SQLException:Field ' address_id ' doesn ' t have a default value

is very puzzled, obviously my address_id is the primary key, for Mao also hint I do not exist default value? Should the primary key not automatically generate values?

Solve is on the one hand, know why the error is the most important.

Cause of Error:

Here are some of the mistakes I've taken (address_id)

Import Java.util.hashset;import java.util.set;import Javax.persistence.*;import Javax.persistence.entity;import Javax.persistence.generatedvalue;import Javax.persistence.generationtype;import javax.persistence.Table;@ Entity@table (name= "Personset_inf") public class Personset {@Id @column (name= "person_id")/* @GeneratedValue (strategy= generationtype.identity) */private Integer id;private string name;private string age;

at the beginning, although I specified the primary key and the primary key name, but did not set the address_id as the primary key @GeneratedValue (strategy=generationtype.identity) Self-increment type (the above code is annotated), the running program console will error:

Exception in thread ' main ' org.hibernate.id.IdentifierGenerationException:ids for this class must is manually assigned be Fore calling Save (): Com.mao.PersonSet

Although the error is reported, hibernate has created a table (Personset_inf), note that the table's primary key is not self-growing mode,

And the data you want to insert is not plugged in, you find the error, and then you add the self-growth type to the primary key in the program and rerun the project, you will get a bug:

Exception in thread ' main ' org.hibernate.exception.GenericJDBCException:could not execute statementcaused by: Java.sql.SQLException:Field ' address_id ' doesn ' t have a default value

The reason is: Although you modify the primary key type in the code, but your database table has been built, its primary key is still not self-growth type, the ID is not automatically assigned, and then error: ID has no default value.

Solution:

First confirm that the program has identified the primary key mode, and then delete the database table, rerun the program, create a data table with the primary key mode, so that you can, and the data is successfully inserted into it.

Hibernate in caused By:java.sql.SQLException:Field ' address_id ' doesn ' t has a default value