I have created tables in MySQL Workbench as shown below :
ORDRE table:
CREATE TABLE Ordre (
OrdreID INT NOT NULL,
OrdreDato DA
You must delete data in the child table which does not have any corresponding foreign key value to the parent table primary key .Or delete all data from the child table then insert new data having the same foreign key value as the primary key in the parent table . That should work . Here also a youtube video