Issues with Access where I am using multiple or statments and Access freezes

[taki]

Trying to use multple 'or' condition and Access freezes but when I remove the 'or' condition and leave only the last set of 'Or', it works.

SELECT ....
FROM tabel1, table2, table3, table4
WHERE ((table1.xxxx=table2.xxxx And table1.xxxx=table3.xxxx And table1.xxxx=table4.xxxx) Or (table1.yyyy=table2.yyyy And table1.yyyy=table3.yyyy And table1.yyyy=table4.yyyy) Or
(table1.wwww=table2.wwww And table1.wwww=table2.wwww))

------ The below statement works if I remove the 'Or' check above ----

And (table1.[zzzz]<>table2.[zzzz] Or table1.[zzzz]<>table3.zzzz Or table1.[zzzz]<>table4.zzzz);

[Stewart Ross]

Hi. The simplified query you have posted does not help us here, as there is no way we can tell what might or might not be happening when you run it.

Are you sure that Access is freezing? It could be that the query is just taking a very long time to run. This can happen if you miss out joins between tables, for instance, in which case the number of rows you expect the query to deal with will be multiplied to a possibly extreme extent, preventing Access from returning anything useful to you even after a long time running.

When no joins are present you get the Cartesian Product of the tables concerned - so if table 1 had 1000 rows and table 2 10000 the product of the two would contain 10,000,000 rows.

I doubt that it is the OR part that is responsible, but I'd need to see the real query - not the altered version you've posted - even to hazard a guess at this.

To repeat, I'd check the joins - you have not shown any in the sample code, which will multiply all four tables together causing a real headache for Access in trying to run the query.

-Stewart