c# 使用文本框搜索连接列

Question

如何搜索串联的列？我知道如何进行单列搜索，但我想要的是搜索连接的列。请帮助我

public void searchenrolee()
    {
        MySqlCommand cmd = connection.CreateCommand();
        MySqlDataAdapter adap = new MySqlDataAdapter(cmd);

        try
        {
            connection.Open();

            string value = "Fullname";

            cmd.CommandText = String.Format(
                        @"Select EEid, CONCAT(Fname,' ', Mname,' ', Lname) AS Fullname, DateRegistered
                        from studenttbl
                        where {0} like @searchKey AND year(DateRegistered) = '" + cbStudYear.selectedValue.ToString() + "' AND Enrollingto = '" + cbSLGrade.selectedValue.ToString() + "' order by EEid desc", value);

            cmd.Parameters.AddWithValue("@searchKey", '%' + tbsearchEnrolee.Text.ToString() + '%');
            MySqlDataAdapter kuhain = new MySqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            adap.Fill(ds);
            dgvStudentList.DataSource = ds.Tables[0].DefaultView;

            connection.Close();
        }
        catch
        {
            connection.Close();
        }
    }

    private void tbsearchEnrolee_TextChanged(object sender, EventArgs e)
    {
        searchenrolee();
    }

Answer 1

Crowcoder 的回答

public void searchenrolee()
{
    MySqlCommand cmd = connection.CreateCommand();
    MySqlDataAdapter adap = new MySqlDataAdapter(cmd);

    try
    {
        connection.Open();

        string value = "Fullname";

        cmd.CommandText = String.Format(
                    @"Select EEid, CONCAT(Fname,' ', Mname,' ', Lname) AS Fullname, DateRegistered
                    from studenttbl
                    where CONCAT(Fname,' ', Mname,' ', Lname) like @searchKey AND year(DateRegistered) = '" + cbStudYear.selectedValue.ToString() + "' AND Enrollingto = '" + cbSLGrade.selectedValue.ToString() + "' order by EEid desc", value);

        cmd.Parameters.AddWithValue("@searchKey", '%' + tbsearchEnrolee.Text.ToString() + '%');
        MySqlDataAdapter kuhain = new MySqlDataAdapter(cmd);
        DataSet ds = new DataSet();
        adap.Fill(ds);
        dgvStudentList.DataSource = ds.Tables[0].DefaultView;

        connection.Close();
    }
    catch
    {
        connection.Close();
    }
}

private void tbsearchEnrolee_TextChanged(object sender, EventArgs e)
{
    searchenrolee();
}