How can I write variable in sub query

i try to write variable in sub query like this :

exec(conn,['select course_id from course where course_id not in' (['select course_id from transcript where student_id=' '''' aa2 '''']) ]);

not respond

Thank you.

Answer 1

[the cyclist]

I think the following is what you want:

 >> queryText = ['select course_id from course where course_id not in (select course_id from transcript where student_id=',num2str(aa2),')'];
 >> exec(conn,queryText)

[sayer ali]

thank you very much the command work perfectly

Answer 2

[the cyclist]

Is aa2 a numeric variable, or a string? You might need to use the num2str() function.

I can't fully debug this right now, but in a case like this, I recommend building your string up piece by piece, outside the exec() function, to make sure the string you send as a query really looks like you expect it to. Looks to me that, for example, you do not really have the parentheses in there as part of the string, the way you want to for a subquery.

[sayer ali]

aa2 is numeric ,i try the same query in ms sql it respond like this

select course_id from course where course_id not in (select course_id from transcript where student_id=7000032);

it respond

you knew when you write this query in mat lab with variable will be somehow different