如何將具有外鍵約束的記錄刪除到另一個表中？

Question

當我試圖刪除datagridview的行見表彩，我得到這個錯誤是：

類型「System.Data.SqlClient.SqlException」 未處理的異常出現在system.data.dll附加信息：DELETE 聲明與參考約束 「FK_NatureCharge_Famille」衝突。衝突發生在數據庫 「Tresorerie」，表「dbo.NatureCharge」，列'IdFam'。陳述 已被終止。

此表（彩和NatureCahrge）
順便說一句，在彩的部分可以在DataGridView中刪除多行。 我嘗試添加刪除NaturCharge第一（它開始於評論刪除自然）
的代碼：

private void DeleteFamBtn_Click(object sender, EventArgs e) 
    { 
     List<DataGridViewRow> selectedRows = (from row in DataGridViewFamille.Rows.Cast<DataGridViewRow>() 
               where Convert.ToBoolean(row.Cells["checkBoxColumn"].Value) == true 
               select row).ToList(); 


     if (MessageBox.Show(string.Format("Do you want to delete {0} rows?", selectedRows.Count), "Confirmation", MessageBoxButtons.YesNo) == DialogResult.Yes) 
     { 
      //delete Nature de Charge before delete Famille 
      foreach (DataGridViewRow row in selectedRows) 
      { 
       try 
       { 
        using (SqlConnection con = new SqlConnection(connstring)) 
        { 
         con.Open(); 
         using (SqlCommand command = new SqlCommand("DELETE NatureCharge FROM NatureCharge n INNER JOIN Famille f on n.IdFam = f.IdFam WHERE IdNat = @IdNat", con)) 
         { 
          command.Parameters.AddWithValue("@IdFam", row.Cells["IdFam"].Value); 
          command.ExecuteNonQuery(); 
         } 
         con.Close(); 
        } 
       } 
       catch (SystemException ex) 
       { 
        MessageBox.Show(string.Format("An error occurred: {0}", ex.Message)); 
       } 

      } 

      //Delete Famille 
      foreach (DataGridViewRow row in selectedRows) 
      { 
       using (SqlConnection con = new SqlConnection(connstring)) 
       { 
        using (SqlCommand cmd = new SqlCommand("DELETE FROM Famille WHERE IdFam = @IdFam", con)) 
        { 
         cmd.CommandType = CommandType.Text; 
         cmd.Parameters.AddWithValue("@IdFam", row.Cells["IdFam"].Value); 
         con.Open(); 
         cmd.ExecuteNonQuery(); 
         con.Close(); 
        } 
       } 
      } 

      //Update the datagridview 
      this.BindGrid(); 
     } 
    } 

錯誤示出了具有線（它是用於彩部分） `cmd.ExecuteNonQuery（）;` '

附加信息：DELETE語句與參考約束「FK_NatureCharge_Famille」衝突。數據庫「Tresorerie」中的 發生衝突，表「dbo.NatureCharge」，列'IdFam'。

它看起來DELETE語句似乎不正確

更新代碼

//delete Nature de Charge before delete Famille 
      foreach (DataGridViewRow row in selectedRows) 
      { 
       try 
       { 
        using (SqlConnection con = new SqlConnection(connstring)) 
        { 
         con.Open(); 
         using (SqlCommand command = new SqlCommand("DELETE NatureCharge FROM NatureCharge n INNER JOIN Famille f on n.IdFam = f.IdFam WHERE IdNat = @IdNat", con)) 
         { 
          command.ExecuteNonQuery(); 
         } 
         con.Close(); 
        } 
       } 
       catch (SystemException ex) 
       { 
        MessageBox.Show(string.Format("An error occurred: {0}", ex.Message)); 
       } 
      } 

和同樣的錯誤......

Answer 1

我這種情況下，我建議你使用級聯刪除外鍵操作，您可以使您的代碼庫比您自己刪除相關的寄存器更簡單。

但是如果你還是想自己做，你可以使用這段代碼，我motified

private void DeleteFamBtn_Click(object sender, EventArgs e) 
{ 
    List<DataGridViewRow> selectedRows = (from row in DataGridViewFamille.Rows.Cast<DataGridViewRow>() 
              where Convert.ToBoolean(row.Cells["checkBoxColumn"].Value) 
              select row).ToList(); 


    if (MessageBox.Show(string.Format("Do you want to delete {0} rows?", selectedRows.Count), "Confirmation", MessageBoxButtons.YesNo) == DialogResult.Yes) 
    { 
     //delete Nature de Charge before delete Famille 
     var idsToDelete = selectedRows.Select(row => row.Cells["IdFam"].Value).ToList(); 
     try 
     { 
      using (var con = new SqlConnection(connstring)) 
      { 
       var ids = string.Join(",", idsToDelete); 
       using (var deleteNatures = new SqlCommand("DELETE FROM NatureCharge IdFam IN " + ids, con)) 
       using (var deleteFamilles = new SqlCommand("DELETE FROM Famille WHERE Id IN " + ids, con)) 
       { 
        deleteNatures.Parameters.AddWithValue("@IdFam", row.Cells["IdFam"].Value); 
        con.Open(); 
        deleteNatures.ExecuteNonQuery(); 
        deleteFamilles.ExecuteNonQuery(); 
       } 

       con.Close(); 
      } 
     } 
     catch (SystemException ex) 
     { 
      MessageBox.Show(string.Format("An error occurred: {0}", ex.Message)); 
     } 

     //Update the datagridview 
     this.BindGrid(); 
    } 
} 

Answer 2

可以刪除所有外通過使用級聯在原始表中記錄關鍵記錄。

在某些DBMS中，它的外鍵約束級別設置了一些，而在刪除本身的級別上。

請查看以下鏈接瞭解更多信息。

http://www.techonthenet.com/sql_server/foreign_keys/foreign_delete.php

Answer 3

我的解決辦法： 之前刪除的表，我必須刪除所有相關的表與相關。 所以我OCDE很簡單，我獲得選擇的DataGridView的IdFam比我刪除與同一ID的行中NatureCharge的表

我的代碼：

private void DeleteFamBtn_Click(object sender, EventArgs e) 
    { 
     List<DataGridViewRow> selectedRows = (from row in DataGridViewFamille.Rows.Cast<DataGridViewRow>() 
               where Convert.ToBoolean(row.Cells["checkBoxColumn"].Value) == true 
               select row).ToList(); 

     if (MessageBox.Show(string.Format("Do you want to delete {0} rows?", selectedRows.Count), "Confirmation", MessageBoxButtons.YesNo) == DialogResult.Yes) 
     { 
      //delete Nature de Charge before delete Famille 
      foreach (DataGridViewRow row in selectedRows) 
      { 
       int aa = Convert.ToInt32(row.Cells["IdFam"].Value); 
       conn = new SqlConnection(connstring); 
       conn.Open(); 
       comm = new SqlCommand("DELETE FROM NAtureCharge WHERE IdFam ='" + aa + "'", conn); 
       try 
       { 
        comm.ExecuteNonQuery(); 
        //MessageBox.Show("Deleted..."); 
       } 
       catch (Exception) 
       { 
        MessageBox.Show("Not Deleted"); 
       } 
       finally 
       { 
        conn.Close(); 
       } 
      } 

      //Delete Famille 
      foreach (DataGridViewRow row in selectedRows) 
      { 
       using (SqlConnection con = new SqlConnection(connstring)) 
       { 
        using (SqlCommand cmd = new SqlCommand("DELETE FROM Famille WHERE IdFam = @IdFam", con)) 
        { 
         cmd.CommandType = CommandType.Text; 
         cmd.Parameters.AddWithValue("@IdFam", row.Cells["IdFam"].Value); 
         con.Open(); 
         cmd.ExecuteNonQuery(); 
         con.Close(); 
        } 
       } 
      } 

      //Update the datagridview 
      this.BindGrid(); 
     } 
    }