mavtech
Posts: 133
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| Posted: 09/27/2004, 1:52 PM |
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I have a grid. With Courses listed on it. when I click on a course I can then see the students listed in another grid on the same page.
I would like to count the number of students in each course and have it displayed in the main grid.
Example:
Course_Name// Course_Date// Number_of_students
So it must count the number of students with the course_name = Course_name
Can somone help.
Paul
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lvalverdeb
Posts: 299
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| Posted: 09/27/2004, 3:22 PM |
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Assuming that you have three tables e.g. courses, students and coursesbystudent (which has a course_id and a student_id fields), I would suggest you try this in the beforeshowrow event:
<code>
global $coursesgrid;
$db = new clsDByourconnection();
$StudentCount = CCDLookUp("count(*)","coursesbystudent","course_id=".$coursesgrid->ds->f("course_id"),$db);
$coursesgrid->number_of_students->SetValue(strval($StudentCount));
unset($db);
</code>
Luis
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lvalverdeb
CR, GMT-6
XAMPP/Ubuntu/CCS3.2/4 |
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mavtech
Posts: 133
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| Posted: 09/28/2004, 6:22 AM |
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There actually is only one table(not my design).
When the table has a RECTYPE = 'P' it is the course name.
When the table has a RECTYPE = 'PC" it is the student name
Both lines will have the same OPID.
Paul
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peterr
Posts: 5971
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| Posted: 09/28/2004, 6:36 AM |
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Just use an SQL query that groups and counts the number of students. If you base a grid on such a query (data source) then it will work automatically and you don't need to do any calculations or lookups in CCS itself.
_________________
Peter R.
YesSoftware Forums Moderator
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mavtech
Posts: 133
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| Posted: 09/28/2004, 7:53 AM |
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Please explain in more detail how to do this ??
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peterr
Posts: 5971
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| Posted: 09/28/2004, 8:27 AM |
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This would probably require teaching the SQL, which is not something that I can do here. Though I can recommend to you some online tutorials on the SQL COUNT function:
http://www.google.com/search?hl=en&lr=&ie=UTF-8&q=sql+count
http://www.google.com/search?hl=en&lr=&ie=UTF-8&q=sql+tutorial+count
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Peter R.
YesSoftware Forums Moderator
For product support please visit http://support.yessoftware.com |
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mavtech
Posts: 133
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| Posted: 09/28/2004, 11:04 AM |
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Whenever I create a label field and set"
Control Source Type to Database Expression and Set
Control Source to something like SELECT COUNT("OPID") FROM "Opmgr" I alway get an syntax error.
What am I doing wrong.
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peterr
Posts: 5971
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| Posted: 09/29/2004, 1:41 AM |
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A SELECT statement is a SQL statement, not an expression. An expression may be COUNT("OPID") but I'm not sure if this will or should work. You should just use the full SQL statement in the datasource of your form (instead of a Table), then simply select the calculated field as the control source of your label.
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Peter R.
YesSoftware Forums Moderator
For product support please visit http://support.yessoftware.com |
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