Question

我正在尝试显示两个日期之间的学生个人出勤记录。当教师选择两个日期时，记录将显示在GridView控件中。但是，我也有其他学生的出勤记录也被显示的问题。我不能只显示学生出勤记录。

一旦老师点击查看按钮，这就是我的C＃代码：

protected void ButtonView_Click(object sender, EventArgs e)
{
    SqlConnection con = new SqlConnection();
    con.ConnectionString = "Data Source=DESKTOP-H7KQUT1;Initial Catalog=SAOS;Integrated Security=True";
    con.Open();

    string query1 = "SELECT * FROM attendance WHERE Date between '" + datepicker.Text + "'AND'" + datepicker1.Text + "'";
    SqlCommand sqlcomm = new SqlCommand(query1, con);

    SqlDataAdapter sda = new SqlDataAdapter(sqlcomm);
    DataTable dt = new DataTable();
    sda.Fill(dt);

    SqlDataReader sdr = sqlcomm.ExecuteReader();

    if (sdr.Read())
    {
        GridView1.DataSource = dt;
        GridView1.DataBind();
    }
    else
    {
        Label7.Text = "No records found!!";
    }

    con.Close();
}

问题在这里：

 string query1 = "SELECT * FROM attendance WHERE Date between '" + datepicker.Text + "'AND'" + datepicker1.Text + "'";

我有一个名为Student_ID的列作为表出席人数的外键。

Answer 1

string query1 = "SELECT * FROM attendance WHERE Date between @startDate AND @endDate and Student_ID = @studentId";

SqlCommand sqlcomm = new SqlCommand(query1, con);
sqlcomm.Parameters.Add("@startDate", SqlDbType.Date).Value = datepicker.Text;
sqlcomm.Parameters.Add("@endDate", SqlDbType.Date).Value = datepicker1.Text;
sqlcomm.Parameters.Add("@studentId", SqlDbType.Int).Value = 100;

SQL Server中的Select语句

1 个答案: