ERROR 1452: Cannot add or update a child row: a foreign key constraint fails

Question

I have created tables in MySQL Workbench as shown below :

ORDRE table:

CREATE TABLE Ordre (
  OrdreID   INT NOT NULL,
  OrdreDato DA         


        

Answer 1

in the foreign key table has a value that is not owned in the primary key table that will be related, so you must delete all data first / adjust the value of your foreign key table according to the value that is in your primary key