How to store value of SqlDataReader in an array?

Question

The course_id inside the while loop have multiple values. i wanted to display all values in GridView, but only last value is being displayed. how can i do that? do i have to store course_id in an array?

int course_id=0;
string query_select_course = "SELECT course_id FROM course_program where program_id = '" + program_id + "' ";

SqlDataReader dr_course = DataAccess.selectDataReader(query_select_course);
while (dr_course.Read())
{
  course_id = (int)dr_course.GetValue(0); // this course_id should have multiple values.
}
dr_course.Close();

string query_select_course_name = "SELECT course_title FROM courses where course_id = '" + course_id + "' ";
DataTable dt = DataAccess.selectData(query_select_course_name);
course_dataGridView.DataSource = dt;

You don't need two queries to get your values. JOIN sql clause allows you to do your work with just one query — Steve
– Steve, Commented Jun 11, 2016 at 11:55

Mairaj Ahmad · Accepted Answer · 2016-06-11 11:56:37Z

4

Make a List<int> and add values in it.

List<int> course=new List<int>();
while (dr_course.Read())
{
 course.Add((int)dr_course.GetValue(0));
}

answered Jun 11, 2016 at 11:56

Mairaj Ahmad

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1 Comment

Alex W Over a year ago

You will need to use something like this as well

string query_select_course_name = "SELECT course_title FROM courses where course_id IN ('" + string.Join("','", course) + "')";

Soner Gönül · Accepted Answer · 2016-06-11 11:55:10Z

1

Since you iterate your reader, your course_id will be the cell value of the last row.

I suggest you to create a List<int> and add those course_id inside your while statement, use string.Join to generate with comma delimiter string with those values like 1, 2, 3, use IN clause instead = inside in your query like;

course_id IN (1, 2, 3)

answered Jun 11, 2016 at 11:55

Soner Gönül

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1 Comment

Umama Khalid Over a year ago

but than how i will display all values in gridview?

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