>>You can use IN operator
>>

>>  Thread.NoClient IN (44,99,51,...52)
>>

>
>Is this ANSI SQL? Basically, will this work as is for VFP and SQL Server?
>
>As for the ISNULL(), I have to call a method in my data provider class to adjust as per the backend for the proper syntax. But, whenever I can use ANSI SQL syntax, it is much better.

Yes IN is standard SQL operator. There is also standard IS NULL operator

Thread2.Numero IS NULL