我的一个字段值只能在第一行成功显示。后续行没有

Question

我有一个约会表单，它将根据约会表格在gridview中显示数据。预约表与患者和医疗中心表有关系。我编写了select语句，以便PatientID将更改为患者表中的pFirstName，并且mcID将更改为medicalcentre表中的mcCentre。奇怪的是pFirstName没有问题，但mcCentre在第一行之后没有显示。如果我没有外部连接并将其保留为mcID，则它将在所有行上显示mcID。

外部联接之前的约会表单的MY DATAGRID，显示mcID

外部联接后的约会表单的MY DATAGRID，从mcID更改为mcCentre

我的任命，患者，医疗中心

//外部联接后的MY约会表单，从mcID更改为mcCentre代码

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Web;
    using System.Web.UI;
    using System.Web.UI.WebControls;
    using System.Data.SqlClient;
    using System.Configuration;
    using System.Data;

public partial class member_viewappointment : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (Page.IsPostBack == false)
        {
            // call BindGridView
            bindGridView();

        }
    }

    private void bindGridView()
    {
        int ID = Convert.ToInt32(Session["ID"].ToString());
        //get connection string from web.config
        string strConnectionString = ConfigurationManager.ConnectionStrings["sacpConnectionString"].ConnectionString;
        SqlConnection myConnect = new SqlConnection(strConnectionString);

        string strCommandText = "SELECT aStatus, aDate, aTime, aContact, aHeight, aWeight, med.mcCentre, pat.pFirstName from appointment AS app ";
        strCommandText += " LEFT OUTER JOIN MEDICALCENTRE as med on app.appointmentid = med.mcid";
        strCommandText += " LEFT OUTER JOIN PATIENT as pat on app.patientid = pat.patientid ";
        //strCommandText += " WHERE app.patientid = " + ID.ToString();

        try
        {
            SqlCommand cmd = new SqlCommand(strCommandText, myConnect);

            myConnect.Open();
            SqlDataReader reader = cmd.ExecuteReader();

            DataTable dt = new DataTable();
            dt.Load(reader);
            grdViewAppointment.DataSource = dt;
            grdViewAppointment.DataBind();
            lblResult.Text = "";

            reader.Close();
        }
        catch (SqlException ex)
        {
            lblResult.Text = "Error:" + ex.Message.ToString();
        }
        finally
        {
            myConnect.Close();
        }

    }
}

Answer 1

您在MEDICALCENTRE

上加入app.appointmentid = med.mcid表格

LEFT OUTER JOIN MEDICALCENTRE as med on app.appointmentid = med.mcid

看起来不对。看起来你打算加入app.mcid = med.mcid

LEFT OUTER JOIN MEDICALCENTRE as med on app.mcid = med.mcid