delete record with foreign key constraint to another table

Question

When I tried to delete row from datagridview refer to table Famille, I get this error is :

An unhandled exception of type 'System.Data.SqlClient.SqlException' occurred in System.Data.dll Additional information: The DELETE statement conflicted with the REFERENCE constraint "FK_NatureCharge_Famille". The conflict occurred in database "Tresorerie", table "dbo.NatureCharge", column 'IdFam'. The statement has been terminated.

Table Famille

IdFam int
NomFam varchar(50)

Table NatureCharge

IdNat int
NomNat varchar(50)

IdFam int

By the way, the Famille part can delete multiple row in datagridview. I tried to add delete the NaturCharge 1st (it begins with comment delete Nature)
The code in the rar file :

an error shows with line (it is for Famille part) `cmd.ExecuteNonQuery();``

Additional information: The DELETE statement conflicted with the REFERENCE constraint "FK_NatureCharge_Famille". The conflict occurred in database "Tresorerie", table "dbo.NatureCharge", column 'IdFam'.

It looks The DELETE statement doesn't seem to be correct

and the same error...

Francis · Answer

Your table have foreign key relationship. So in order to delete the row from the child table then you need to delete the respective record in Master table then you can able to delete in the child table. In your case table  NatureCharge contains the column IdFam where it has a foreign key reference with the table Familee with the column IdFam. In order to solve this: First delete from the record from the table NatureCharge. Second delete the record from the table Familee. If you didn't follow the above sequence you will get the error! Hope this helps!

Francis · Answer

So your code working fine. If so accept the reply as answer that helps you. :)

Med Amin · Answer

no :)

Francis · Answer

Have you got any error while deleting?

Med Amin · Answer

yes that is the solution : and my code is : //delete Nature de Charge before delete Famille foreach (DataGridViewRow row in selectedRows) { int IdFamDeletedValue = Convert.ToInt32(row.Cells[IdFam].Value); conn = new SqlConnection(connstring); conn.Open(); comm = new SqlCommand(DELETE FROM NAtureCharge WHERE IdFam =' + IdFamDeletedValue + ' conn); try { comm.ExecuteNonQuery(); //MessageBox.Show(Deleted...); } catch (Exception) { MessageBox.Show(Not Deleted); } finally { conn.Close(); } }