Hello All,

I often see this syntax:

SELECT a.col1, b.col2, c.col3
FROM table1 a
INNER JOIN table2 b ON a.col1 = b.col2
INNER JOIN table3 c ON b.col2 = c.col3
WHERE a.col1 = 147

while some are writing:

select a.col1, b.col2, c.col3
from table1 as a,
table2 as b,
table3 as c
where a.col1 = b.col2
and b.col2 = c.col3
and a.col1 = 147

Q1: are there any diffrences ? why should i prefer one syntax above the other ?
Q2: assume this is the query, should this bring better results:

select a.col1, b.col2, c.col3
from table1 as a,
table2 as b,
table3 as c
where a.col1 = 147
and b.col2 = 147
and c.col3 = 147

thanks
Chanan

Q1. yes there are differences

when they are inner joins, the results produced are the same, although the query with INNER JOINs is a lot easier to understand than the one with the old style comma joins

however, when you need an outer join, the old style comma joins just cannot accomplish it

Q2. no, same results