sql - How to find out duplicate records from multiple tables in MS Access based on two condition

Question

How to find out duplicate records from multiple tables in MS Access based on month and the below columns ? Name, Text, Description, TestDescription

select [table1].[Name], [table1].[Text], [table1].[Description], [table1].[TestDescription] 
From [table1]
UNION ALL 
select  [table2].[Name], [table2].[Text], [table2].[Description], [table2].[TestDescription]
from [table2]
WHERE Table1.month IN ("April","May") and Table2.month IN ("April","May")
group by [table1].[Name], [table1].[Text], [table1].[Description], [table1].[TestDescription]
having count(*) > 1;

Answer 1

Each SELECT in a UNION is it's own seperate query, so you can't do two WHERE clauses at the bottom. Each part must have it's own WHERE and each part doesn't know about the other part (it's out of context). Instead treat the entire UNION result set as a subquery to do your GROUP BY... HAVING test:

SELECT *
FROM
    (
        SELECT [table1].[Name], [table1].[Text], [table1].[Description], [table1].[TestDescription] 
        FROM [table1]
        WHERE Table1.month IN ("April","May") 
        UNION ALL 
        SELECT  [table2].[Name], [table2].[Text], [table2].[Description], [table2].[TestDescription]
        FROM [table2]
        WHERE Table2.month IN ("April","May")
    ) AS myUnion
GROUP BY [myUnion].[Name], [myUnion].[Text], [myUnion].[Description], [myUnion].[TestDescription]
HAVING COUNT(*) > 1;