C# & SQL Server 查询错误 : The multi-part identifier cannot be bound

Question

protected void btnSubmit_Click(object sender, EventArgs e)
{
    connectionString = ConfigurationManager.ConnectionStrings["LeaveMangementSystemCS"].ConnectionString;
    conn = new SqlConnection(connectionString);
    string sql = "UPDATE LeaveType  SET LeaveType.Type=@Type, LeaveType.Description=@Description, LeaveType.NumOfDays=@NumOfDays, LeaveCategory.Category=@Category FROM LeaveType INNER JOIN LeaveCategory on LeaveType.LeaveCategoryId = LeaveCategory.Id  WHERE LeaveType.Id=@id";

    try
    {
            cmd = new SqlCommand(sql, conn);
            cmd.Parameters.AddWithValue("@Type", tbType.Text);
            cmd.Parameters.AddWithValue("@Description", tbDescription.Text);
            cmd.Parameters.AddWithValue("@NumOfDays",tbNumOfDays.Text);
            cmd.Parameters.AddWithValue("@Category", ddlLeaveCategory.Text);
            cmd.Parameters.AddWithValue("@id", lblIdOut.Text);

            conn.Open();
            int rows = cmd.ExecuteNonQuery();

            if (rows > 0)
            {
                lblOutput.Text = " Updated successfully.";
            }
    }
    catch (Exception ex)
    {
        lblOutput.Text = "Error Message : " + ex.Message;
    }
    finally
    {
        if (conn != null)
            conn.Close();
    }
}

我的 SQL 查询有一个错误:

The multi-part identifier "LeaveCategory.Category" could not be bound.

我曾尝试使用 leavetype 作为 a 和 leavecategory 作为 b 但仍然是这个错误。

Answer 1

您不能在一个语句中更新多个表!查看您的 sql 变量:

UPDATE LeaveType  
SET LeaveType.Type=@Type
,   LeaveType.Description=@Description
,   LeaveType.NumOfDays=@NumOfDays
,   LeaveCategory.Category=@Category 
FROM LeaveType 
INNER JOIN LeaveCategory on LeaveType.LeaveCategoryId = LeaveCategory.Id  
WHERE LeaveType.Id=@id";

在这里，您尝试更新表 LeaveType 和表 LeaveCategory 中的一列

请参阅this回答