Dynamic Query Criteria - ms-access

Question

I'm trying to make a Microsoft Access query depend on a value in another form's textbox.
This is the criteria, as it is now. Basically, any date between April 1st 2014, and March 31st 2015. This works well.
>=#2014-04-01# And <#2015-04-01#
I'd like to have a textbox with the year (with the current example 2014), and make the query criteria (2014, 2014+1) depend on this value.
I've tried to split the above syntax, then concatenate in the criteria, as such:
">=#" & "2014" & "-04-01# And <#" & "2015" & "-04-01#"
And I get an error "Data types in the criterion expression are incompatible".
1. Is it possible to concatenate in the query criteria?
I have also tried the SQL CONCAT(string1,string2,string3,..), to no avail.
If this is possible, then I guess I can use [Forms]![Form1].[Textbox1] and ([Forms]![Form1].[Textbox1] + 1) to replace the years.
If this is not possible...
2. Is there a better way to make the query criteria dynamic?
I tried to make the following solution work by creating a module with similar code:
Private m_varQueryParam As Variant
Public Function SetQueryParam(ByVal sValue as Variant)
m_varQueryParam = sValue
End Function
Public Function GetQueryParam() As Variant
GetQueryParam = m_varQueryParam
End Function
Query:
SELECT * FROM tblYourTable WHERE [FilterField] = GetQueryParam()
The VBA Code to launch the query will look like this.
SetQueryParam "your value here"
DoCmd.OpenQuery "qryYourQueryHere"
But I simply do not understand how to get this to work.
EDIT: I created a simple access database, to try to get this to work.
Textbox1, default value =Date()
bSave, button
tDateInfo, table: date (date/time), info (text) with random dates and info.
Query1:
SELECT tDateInfo.date, tDateInfo.info
FROM tDateInfo
WHERE (((tDateInfo.date)=GetQueryParam()));
Here's the form's vba code
Option Compare Database
Private Sub bSave_Click()
sValue = Me.TextBox1.Value
SetQueryParam (sValue)
End Sub
Here's the modules vba code
Option Compare Database
Option Explicit
'is this necessary?
Private m_varQueryParam As Variant
Public Function SetQueryParam(ByVal sValue As Variant)
m_varQueryParam = sValue
End Function
Public Function GetQueryParam() As Variant
GetQueryParam = m_varQueryParam
End Function
And the query criteria is GetQueryParam()
Thank you for your help.

Answer 1

Handling parameters and form fields is a little tricky with VBA. I created a simple table similar to yours as follows:
CREATE TABLE DateCalc (
ID AutoNumber,
FilterField DateTime
)
The following code will return your desired results:
Sub testthis()
Dim db As dao.database
Set db = CurrentDb ' use current database
Dim qd As dao.QueryDef
Set qd = db.CreateQueryDef("") ' create anaonymous querydef
' the SQL statement correctly concatenates the parameter (Useyear) and mm/dd strings
qd.sql = "SELECT * FROM DateCalc WHERE [FilterField] >= [UseYear]" & "-04-01 And [FilterField] < [UseYear]+1" & "-04-01"
qd!UseYear = Forms!DateCalc!txtYear ' set the value of se year from the Form WHICH MUST BE OPEN
' AND the TetBox filled with the year you desire - 2014 for this example.
Dim rs As dao.recordSet
Set rs = qd.OpenRecordset
MsgBox "ID=" & rs(0) & ", Date=" & rs(1)
End Sub
NEW VERSION
Sorry, there were a couple of date formatting problems with the first solution that the following code resolves. There are a number of other reasons for the error, so be sure the FormName is "DateCalc" and the TextBox is named "txtYear".
You should be able to generalize the following code for all your queries (do those actually work?). I pass the TableName in now as an example:
Sub DateFilter(TableName As String)
Dim db As dao.database
Set db = CurrentDb ' use current database
Dim qd As dao.QueryDef
Set qd = db.CreateQueryDef("") ' create anaonymous querydef
' the SQL statement correctly concatenates the parameter (Useyear) and mm/dd strings
Dim UseYear As Integer
UseYear = Forms!DateCalc!txtYear
Dim BegDate As Date
BegDate = CDate(UseYear & "-04-01")
Dim EndDate As Date
EndDate = CDate((UseYear + 1) & "-04-01")
qd.sql = "SELECT * FROM " & TableName & " WHERE [FilterField] >= [UseBegDate] And [FilterField] < [UseEndDate]"
qd!UseBegDate = BegDate
qd!UseEndDate = EndDate
Dim rs As dao.recordSet
Set rs = qd.OpenRecordset
Do While Not rs.EOF
MsgBox "ID=" & rs(0) & ", Date=" & rs(1)
rs.MoveNext
Loop
End Sub

Answer 2

I think I found a solution.
The following code defines the SQL as I require it, and changes the SQL for the Access query.
It's not ideal, because it requires me to rewrite all the SQL for the queries, but it works.
Sub ChangeQuery()
Dim Year, sqlTwo, StartDate, EndDate As String
Year = Me.txtYear.Value
StartDate = "4/1/" & Year
EndDate = "4/1/" & (Year + 1)
sqlTwo = "SELECT DateCalc.ID, DateCalc.FilterField FROM DateCalc WHERE (((DateCalc.FilterField)>=#" & StartDate & "# And DateCalc.FilterField<#" & EndDate & "#));"
tbTest.Value = sqlTwo
Dim oDB As Database
Dim oQuery As QueryDef
Set oDB = CurrentDb
Set oQuery = oDB.QueryDefs("Query1")
oQuery.SQL = sqlTwo
Set oQuery = Nothing
Set oDB = Nothing
End Sub
Private Sub Button_Click()
ChangeQuery
End Sub