Wednesday, June 27, 2007

Watch Out - Order of Inner Joins

Just a quick one here - when porting SQL statements from mySQL to MSSQL - you need to mind the order of your joins. Whereas mySQL likely re-orders the joins so that columns used in one join is available to the next, MSSQL quickly barks at you unless your join your tables in the order so that you never reference a table not already previously mentioned in the SQL statement.

Pretty linear limitation for a product which is completely based on set theory relation rather than linearity.

1 comment:

Anonymous said...

Good words.