Could not execute JDBC batch update

Question

i have a little trouble while making my first play application.

I got a class Meal which can have one or more MealEntries in it. One meal entry can be used by several meals (i.e if u eat 2 eggs for more than one meal). But im getting a exception.

I can understand why i get the exception, but i cant figure how i can cure it.

This is my exception:

Caused by: java.sql.BatchUpdateException: Duplicate entry '4' for key 'mealEntries_id'
    at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:2020)
    at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:1451)
    at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeBatch(NewProxyPreparedStatement.java:1723)
    at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)
    at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)
    ... 12 more

Meal Class:

public class Meal extends Model {
public String name;
public Date consumed;

@OneToMany
public List<MealEntry> mealEntries;
}

MealEntry Class:

public class MealEntry extends Model {
public int amount;

@OneToOne
public Unit unit;

@OneToOne
public FoodType type;

@OneToOne
public MealEntry with;
}

Thanks in advance

Edit: Tried to create a testcase, but ran into some other error. I'll try to explain: The exception happens when i try to create a second meal, using MealEntries that are also used by the first Meal.

Solution 1

Thanks for the feedback, but i figured it out.

I changed my Meal to MealEntry relation to @ManyToMany and it solved the problem.

Solution 2

Looks like you have a database constraint that does not allow you to insert these duplicates. Update your database structure or find a way to represent the meal in the current structure.