Hi,

I have been looking at some old querys on a DBISAM 3.30 database.  I was wondering why the
following SQL works without a WHERE.  

Is WHERE not required?


SELECT STAFF_ID, FIRST_NAME, SURNAME,
SUM(TOTAL_PRICE - TOTAL_DISCOUNT_ALLOCATION) 'SALES',
BRANCH_NAME, BRANCH_ID, TILL_ID
FROM NORMALTRANLOG NTLOG
INNER JOIN STAFF ON (STAFF.STAFF_ID = STAFF_ID)
INNER JOIN BRANCH ON (BRANCH.BRANCH_ID = CAST(NTLOG.BRANCH_ID AS INTEGER))
AND DATE >= '2005-01-01'
AND DATE <= '2006-01-01'

GROUP BY STAFF_ID, BRANCH_ID, TILL_ID
ORDER BY SURNAME ASC, FIRST_NAME ASC


Thanks Stuart

Stuart Kelly wrote:
> Hi,
>
> I have been looking at some old querys on a DBISAM 3.30 database.  I
> was wondering why the following SQL works without a WHERE.
>
> Is WHERE not required?

No.

Ralf

Stuart,

> I have been looking at some old querys on a DBISAM 3.30 database.  I was wondering why the
> following SQL works without a WHERE.  
>
> Is WHERE not required?

It works because in SQL89 there was no JOIN keyword and joins therefore
had to be expressed as WHERE conditions. In order to maintain backward
compatibility with SQL89 while also supporting SQL92 most engines
therefore lump both JOIN and WHERE conditions together for processing
and as a side effect allow you to create (logically) badly formed
expressions like the one you quoted.

Eryk