How to build query WHERE X OR HAVING Y

Question

My data is a parent table named sales and a child table named sale_lines . I'd like to select all records from the sales table where sale.customer_id=X OR SUM(sale_lines.total)>=Y .

The customer_id condition will go in the WHERE clause and it makes sense to have the SUM(sale_lines.total)>Y in the HAVING clause. My problem is how to have a logical OR between the WHERE and HAVING clauses. Is this possible? If so, how?

I know how to do this with a sub-query, but I'm trying to develop an automated query generation solution and I'd like to avoid the complexity of dealing with sub-queries.

Answer 1

You need to do this in the having clause:

select . . .
from . . .
group by s.customer_id, . . .
having s.customer_id = X or sum(s.total) > Y;

The query might look like:

select s.customer_id, sum(s.total)
from sales s
group by s.customer_id
having s.customer_id = X or sum(s.total) > Y;

Because of the or , you cannot filter before aggregation.

Actually, if you want the records from the sales table (and not the aggregations), then something like this is appropriate:

select s.*
from sales s
where s.customer_id = X or
      s.customer_id in (select s2.customer_id
                        from sales s2
                        group by s2.customer_id
                        having sum(s2.total) > Y
                       );