I'm trying to trace some SQL in Microsoft Server. I came across a join that is using a convention unfamiliar to me. What does "=*" mean?
WHERE table1.yr =* table2.yr -1
What does =* mean?
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11 Answers
To be plain and simple. This is a SQL-92 outer join operator ( more info )
Don't use it, its very old school, but its similar to LEFT JOIN, and RIGHT JOIN. All its doing is telling which side of the join is the "Parent" side, so rows on that side will be considered first.
If you try to run this on SQL 2005, it will throw an error, saying that you need to run this in compatibility mode.
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