Question

您好我想从我的表中删除一行，我有3个表用于食谱，成分，我使用第3个表来组合食谱和成分表，

我的问题我可以添加一行，但我不知道如何删除一行我真的不知道该怎么做。

代码向下plz帮助^^“

private void btnAddToRecpie_Click(object sender, EventArgs e)
    {
        string query = "INSERT INTO RecpieIngredient VALUES (@RecpieId,@IngredientId)";

        using (connection = new SqlConnection(connectionString))
        using (SqlCommand cmnd = new SqlCommand(query, connection))
        {
            connection.Open();
            cmnd.Parameters.AddWithValue("@RecpieId", lstRecpie.SelectedValue);
            cmnd.Parameters.AddWithValue("@IngredientId",lstAllIngredient.SelectedValue);
            cmnd.ExecuteScalar();
        }
        PopulateRecpie();
    }

    private void butToDelete_Click(object sender, EventArgs e)
    {
        string query = "DELETE FROM  RecpieIngredient WHERE (@RecpieId , @IngredientId)=@RecpieId , @IngredientId ";

      //  a.Name FROM Ingredient a INNER JOIN RecpieIngredient x ON a.Id = x.IngredientId INNER JOIN Recpie m ON m.Id=x.RecpieId WHERE m.Id=" + index;
        using (connection = new SqlConnection(connectionString))
        using (SqlCommand cmnd = new SqlCommand(query, connection))
        {
            connection.Open();

            cmnd.Parameters.AddWithValue("@RecpieId", lstRecpie.SelectedValue);
            cmnd.Parameters.AddWithValue("@IngredientId", lstAllIngredient.SelectedValue);

            cmnd.ExecuteNonQuery();

        }
        PopulateRecpie();
    }

Answer 1

此：

INSERT INTO RecpieIngredient VALUES (@RecpieId,@IngredientId)

真的是简写：

INSERT INTO RecpieIngredient (RecpieId, IngredientId) VALUES (@RecpieId, @IngredientId)

DELETE语句没有这样的简写变体，并要求您明确提及列名称：

DELETE FROM RecpieIngredient WHERE RecpieId = @RecpieId AND IngredientId = @IngredientId

你自己解决问题的方法非常接近：）

Answer 2

删除语句错误。它应该是

string query = "DELETE FROM RecpieIngredient 
                         WHERE RecpieId = @RecpieId 
                         AND IngredientId = @IngredientId";

删除一行 - Sql C＃

2 个答案: