SQL Server *= operator

Question

I came across some code with this *= operator in a WHERE clause and I have only found one thing that described it as some sort of join operator for Sybase DB. It didn't really seem to apply. I thought it was some sort of bitwise thing (which I do not know much about) but it isn't contained in this reference at all.

When I change it to a normal = operator it doesn't change the result set at all.

The exact query looks like this:

select distinct 
       table1.char8_column1,
       table1.char8_column2,
       table2.char8_column3,
       table2.smallint_column
from   table1, table2
where  table1.char8_column1 *= table2.another_char8_column

Does anyone know of a reference for this or can shed some light on it? This is in SQL Server 2000.

score 19 · Accepted Answer · edited Aug 15 '13 at 16:13

19

Kill the deprecated syntax if you can, but:

*= (LEFT JOIN)

=* (RIGHT JOIN)

edited Aug 15 '13 at 16:13

marc_s

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answered Aug 15 '13 at 16:07

Hart CO

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score 4 · Answer 2 · answered Aug 15 '13 at 16:04

4

That would be the "old school" equivalent of a LEFT JOIN.

answered Aug 15 '13 at 16:04

Adriaan Stander

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score 3 · Answer 3 · edited May 23 '17 at 11:53

3

It is legacy syntax for specifying outer joins, Microsoft refers to it as "non-ANSI outer join operators". These outer join operators (= and =) are not supported when the compatibility level of the database is set to 90.

This question has been answered on StackOverflow before: What is this operand (*= star-equals) in SQL server 2000?

edited May 23 '17 at 11:53

Community

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answered Aug 15 '13 at 16:16

July.Tech

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SQL Server *= operator

3 Answers3