SQL select returns extra result - sql

Question

Guess there are similar questions and the answere might is easy but I cant help my self and thats why I ask you guys.
I have some Data in a DB (Centura/Gupta SQLBase 7)
no Left/Right Join possible - obviously not implemented in sqlbase sql
Here is my select
SELECT
I.IARTNR,
L.ARTNAME
FROM
INVENTUR I,
LAGER L
WHERE
L.ARTSTR = I.IARTNR
AND
I.AB = '2015-81';
returns 20 rows, not 18 as expacted.
INVENTUR rows with AB set to 2015-81 are 18 and in LAGER there are <3000 rows. What I'm trying to do is select all articles von INVENTUR and add the article name thats written in LAGER.
Whats wrong with my select ? Running this "mysterious" since 3 days.

Answer 1

ANSI join syntax for Outer / Inner joins was added in v8.5 onwards ( now upto v12.1 ).
Before v8.5 , you can use the native Gupta Outer / Inner join syntax e.g.
SELECT t1.col1,t2.col1,t1.col2,t2.col2
FROM t1,t2
WHERE t1.col1 = t2.col1(+)
AND t1.col2 = t2.col2(+)
The next example lists customer names and their order numbers,including customers who have made no orders:
SELECT CUSTOMER.CUSTNO,NAME
FROM CUSTOMER,ORDERS
WHERE CUSTOMER.CUSTNO = ORDERS.CUSTNO(*)
The same query using ANSI syntax in SQLBase v8.5 onmwards is:
SELECT CUSTOMER.CUSTNO,NAME
FROM CUSTOMER LEFT OUTER JOIN ORDERS ON CUSTOMER.CUSTNO = ORDERS.CUSTNO

Answer 2

Use explicit joins.
SELECT I.IARTNR, L.ARTNAME
FROM INVENTUR I
INNER JOIN LAGER L ON I.IARTNR = L.ARTSTR
WHERE I.AB = '2015-81';
And if needs be DISTINCT.
SELECT DISTINCT I.IARTNR, L.ARTNAME
FROM INVENTUR I
INNER JOIN LAGER L ON I.IARTNR = L.ARTSTR
WHERE I.AB = '2015-81';

Answer 3

Of course SQLBase has inner / outer joins !
Either Native syntax ( using (+) ) or ANSI .
Here's the syntax:
NATIVE:
SELECT t1.col1, t2.col1, t1.col2, t2.col2
FROM t1, t2
WHERE t1.col1 = t2.col1 (+) AND t1.col2 = t2.col2 (+);
ANSI:
SELECT t1.col1, t2.col1, t1.col2, t2.col2
FROM t2 RIGHT OUTER JOIN t1
ON t1.col1 = t2.col1
AND t1.col2 = t2.col2 ;
p.s. SQLBase is no 'weird' database . v12 recently released will outstrip SQLServer every time in terms of performance , footprint and overall cost of ownership. Please be more aware of your facts before broadcasting nonsense.