How to use “WHERE” and also “WHERE NOT EXISTS” in the same query and table?

Question

I am trying to add both WHERE and WHERE NOT EXISTS in same query. Below mentioned query1 is working fine, but it returns all the t1 data which does not belong to company1. So I tried query2, but no luck. How can I get the desired result?

1.

select * from t1 where not exists
(select * from t2 inner join t3 on(t3._id = t2.department_id)where t2.category_id = t1._id AND t3._id = 27 AND t3.company_id = 1) 
 ORDER BY "ctsName"

2.

select * from t1 where company_id = 1 AND where not exists
(select * from t2 inner join t3 on(t3._id = t2.department_id)where t2.category_id = t1._id AND t3._id = 27 AND t3.company_id = 1) 
 ORDER BY "ctsName"

Answer 1

WHERE is a separator, not an operation , the bit after WHERE describes the rows you want to see in the result.

To apply two conditons use AND or OR to combine them.

select * from t1 
where not exists (select * from t2 inner join t3 on(t3._id = t2.department_id)
  AND  t2.category_id = t1._id AND t3._id = 27 AND t3.company_id = 1) 
ORDER BY "ctsName"