What are the step to follow in creating custom SQL in webi 3.1 sp5

Hi Friends,

I need you help in understanding the basic steps to follow in custom SQL and their limitations in webi 3.1 sp5.

I have a lots of requirements coming to work in Custom SQL. I have access to do custom SQL and when I tried to modify the existing query like below and its throwing error message.

SELECT E.NAME, E.START_DATE

E.END_DATE,D.DEPT,D.LOCATION,

E.EID

FROM EMP E

INNER JOIN DEPT ON

E.EID=D.EID

Modified Code:

select  e.name,

e.start_date,

e.end_date,

d. dept,sal,

d.dept_location,

e.eid, d.company,d.country, e.last_name, e.first_name,e.start_date,e.job_code,e.grade,

s.salary,s.salary_deposit_date, s.job_code

from emp e

inner join dept on

e.eid=d.eid

inner join salary on

s.job_code=e.job_code and s.sid=e.eid;

KINDLY SUGGEST ME NECESSARY STEPS TO FOLLOW.