>>>There is one important problem in this code sample - the OrderDate is not prefixed with the alias. Without that we would need to check which table this column belongs to.
>>>My rule of thumb - prefix every column with an alias name when the query involves more than 1 table.
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>>I don't disagree with the rule of thumb, especially with several tables. But with 2 tables (a business entity master and a child table of orders), any question about the lineage of OrderDate is more likely a problem with the person in the chair. :)
>>
>
>The rule is the rule - and I always follow it.

My rule says that all fields within a database have a unique name by having a three letter prefix and an underscore for every field in a table, therefore not needing to prefix any field with an alias. As a bonus in the result of the query you always know where the field comes from.

Walter,