What is this operand (*= star-equals) in SQL server 2000?

Question

I have a query that I pulled from ms sql 2000 and plugged into a MySql query. It did not work, MySql would choke on the *= operator. In this example I have two varchar colum

Answer 1

In MSSQL, the *= convention in the WHERE clause indicates a join. So what you are really seeing is a LEFT OUTER JOIN between tbl1 and tbl2 on person_name where all the values from tbl1 and the matching values on tbl2 will be returned.

Answer 2

In SQL 2000 this was used as a LEFT OUTER JOIN

=* is a RIGHT OUTER JOIN

Your query could be:

SELECT 
  * 
FROM 
  tbl1 a LEFT OUTER JOIN tbl2 b ON a.person_name = b.person_name
WHERE 
  a.id = b.id

As stated here:

Specifies an outer join using the nonstandard product-specific syntax and the WHERE clause. The *= operator is used to specify a left outer join and the =* operator is used to specify a right outer join.