SQL Server *= Operator?

Remove this code immediately and replace with a left join. This code does not always interpret correctly (Sometimes SQL Server decides it is a cross join) even in SQL Server 2000 and thus can give incorrect results! Also it is deprecated for the future (Using Outer Joins, SQL Server 2000 documentation archived from the original).

I'm going to add that in adjusting to left joins you should remove all of those other implicit joins as well. The implicit join syntax has been obsolete since 1992, there is no excuse for it still being in production code. And mixing implicit and explicit joins can give unexpected results.

---

It is a left outer join, =* is a right outer join.

E.g. the following are equal;

  SELECT * FROM Table1 LEFT OUTER JOIN Table2 ON Table1.ID = Table2.FK_ID

  SELECT * FROM Table1, Table2 WHERE Table1.ID *= Table2.FK_ID