如何在SQL更新表？

本文介绍了如何在SQL更新表？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

尝试更新在SQL数据库中的表Student_Course，它运行，但我不断收到

I really just need to update the marks value but need to match it to the CID (Course ID) and SID(Student ID)

private void btnAdd_Click(object sender, EventArgs e)
{
    using (SqlConnection con = new SqlConnection(cs))
    {
        try
        {
            using (var cmd = new SqlCommand("UPDATE Student_Course SET CID=@CID,  SID=@SID , Mark=@Mark", con))
            {
                cmd.Connection = con;
                con.Open();
                cmd.Parameters.AddWithValue("@CID", cboCID.GetItemText(cboCID.SelectedItem));
                cmd.Parameters.AddWithValue("@SID", cboSID.GetItemText(cboSID.SelectedItem));
                cmd.Parameters.AddWithValue("@Mark", Convert.ToInt32(txtMark.Text));

                if (cmd.ExecuteNonQuery() > 0)
                {
                    MessageBox.Show("Mark Added");
                }
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show("Error during insert: " + ex.Message);
        }
    }
}

解决方案

"UPDATE Student_Course SET Mark = @Mark WHERE CID=@CID AND SID=@SID"

This should be the correct SQL statement because you are trying to update the Mark field in your Student_Course table based on the CID & SID of the person.

这篇关于如何在SQL更新表？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！

cid

如何在SQL更新表？

问题描述