Why use the Union query at all? Assuming that you only have these four
categories, you could try:

SELECT
Switch([Diabetes_Type]="Type 1","Type 1",
[Diabetes_Type]="Type 2", "Type 2",
Date_of_BirthDateAdd("yyyy",-19,Date()),"Gestational 1-18 years",
Date_of_Birth=DateAdd("yyyy",-19,Date()),"Gestational 19+ years",
True,"Unknown") AS Category, Count(*) AS CountOfID
FROM tbl_Diabetes
GROUP BY
Switch([Diabetes_Type]="Type 1","Type 1",
[Diabetes_Type]="Type 2","Type 2",
Date_of_BirthDateAdd("yyyy",-19,Date()), "Gestational 1-18 years",
Date_of_Birth=DateAdd("yyyy",-19,Date()),"Gestational 19+ years",
True,"Unknown");



--
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HTH
Dale



"John" wrote:

I have, with the help of this newsgroup, created a union query. However I now
need to add a parameter to have it only show me the data for a specific
period of time.
I have pasted the union query sql below.
SELECT "Type 1" AS [Catagory],
COUNT(*) AS [Number of Patients]
FROM [Diabetes]
WHERE Diabetes_Type = "Type 1"
GROUP BY "Type 1"

UNION ALL
SELECT "Type 2",
COUNT(*)
FROM [Diabetes]
WHERE Diabetes_Type = "Type 2"
GROUP BY "Type 2"

UNION ALL
SELECT "Gestational 1-18 years",
COUNT(*)
FROM [Diabetes]
WHERE Diabetes_Type = "Gestational"
AND GetAge([Date_of_Birth]) =18
GROUP BY "Gestational 1-18 years"

UNION ALL SELECT "Gestational 19+ years",
COUNT(*)
FROM [Diabetes]
WHERE Diabetes_Type = "Gestational"
AND GetAge([Date_of_Birth]) =19
GROUP BY "Gestational 19+ years";

As you can see it shows me all of the three different types of diabetes for
the whole database. I need to know how many Type 1 diabetes, Type 2 diabetes
and Gestational diabetes for the two age groups for say the month of January
2009. I tried adding the parameters to the top of the query, it gives me the
places to fill in the dates, but I still get the same numbers for the whole
database.