| Instruct ICC 2007-07-20, 6:59 pm |
| I have a 1 table query which returns less rows than when I have a 2 table
query using an implicit inner join or an explicit left join.
Select some, fields
From table1
Where part like '123%'
/* returns 2225 rows */
Select activePart, some, fields
From table1, table2
Where part like '123%'
and part = activePart
/* implicit inner join returns 2270 rows */
Select activePart, some, fields
From table1 left join table2
On part = activePart
Where part like '123%'
/* explicit left join also returns 2270 rows */
Fields part and activePart are not in table2 and table1 respectively.
I assume I am forgetting something basic this friday. Why would I get more
rows from the above? I might expect more rows from an outer join. Am I
writing an outer join?
After a quick break in the john, I'm thinking perhaps table2 is not holding
unique "part"s as I was told it would. But I'll post this for your thoughts
before I check on that, in case you have other insights.
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