Question

In MySql database have AM_COURSE

UserId      CourseName   course_desc
  101          java        sometext...
  102          mysql       sometext....
   :

AM_TIMETABLE table in that

UserId        Date_Time
 101        2012-08-08 04:00:00 
 102        2012-08-15 10:00:00
 103        2012-08-18 09:00:00
 104        2012-08-24 05:00:00

My Question is, i’m passing start-date and end-date and CourseName then i want to get UserId in that way i wrote query

select UserId,CourseName,course_desc from AM_COURSE where name='java' and UserId=(SELECT UserId FROM AM_TIMETABLE WHERE `Date_Time` BETWEEN '2012-08-07 00:00:00' AND '2012-08-20 00:00:00')

then i will get 101 UserId value.
but i’m getting error because inner query give two id’s… please help

Answer 1

If your inner query is returning more than 1 result (and this is valid of course for your scenario) then shouldn’t you be using the IN clause?

select UserId
,CourseName
,course_desc 
from AM_COURSE 
where name='java' and UserId in (
    SELECT UserId 
    FROM AM_TIMETABLE 
    WHERE `Date_Time` BETWEEN '2012-08-07 00:00:00' AND '2012-08-20 00:00:00'
)