Sergey,

Thanks for your suggestions. I am a SQL novice, so sometimes I don't even know (or remember) some of the basic language syntax. Your response helped me a lot.

David

>David,
>
>>How do I measure query efficiency?
>
>That's what execution plans and tests are for.
>
>>Often, there are multiple ways of writing a single query. For example,
>> 
>>SELECT Table1.Field1
>>FROM   Table1
>>       INNER JOIN Table2
>>       ON Table1.PK1 = Table2.FK2
>>WHERE  Table2.Field2 = value1
>>
>>could be written,
>>
>>SELECT Table1.Field1
>>FROM   Table1
>>       INNER JOIN
>>          (SELECT  Table2.Field2, Table2.FK1
>>           FROM    Table2
>>           WHERE   Table2.Field2 = value1)
>>       ON Table1.PK1 = Table2.FK1
>>
>>or,
>>
>>SELECT Table1.Field1
>>FROM   Table1
>>WHERE  Table1.PK1 IN
>>          (SELECT  Table2.FK1
>>           FROM    Table2
>>           WHERE   Table2.Field2 = value1)
>>
>>Are any of these more efficient than the others?
>
>In my experience, the first one and following one are most efficient but, again, analyze execution plans an run tests.

SELECT Table1.Field1 FROM   Table1
>WHERE  EXISTS (SELECT *  FROM Table2
>           WHERE Table1.PK1 = Table2.FK2
>              AND Table2.Field2 = value1)
>

>
>>The type of query that I am having the most trouble with is when I want to select the rows in a table that don't have their primary keys listed as a foreign key in a table with which it has a 0..* relationship. I have been coding it as,
>>
>>SELECT Table1.Field1
>>FROM   Table1
>>       LEFT OUTER JOIN Table2
>>       ON Table1.PK1 = Table2.PK2
>>WHERE  Table2.FK1 IS NULL
>>
>>Is there a more efficient way to write this query? Microsoft SQL doesn't support MINUS, which would be my first inclination.
>
>I would first try EXISTS query

SELECT Table1.Field1 FROM  Table1
>  WHERE NOT EXISTS (SELECT * FROM    Table2
>           WHERE   Table1.PK1 = Table2.FK2)
>