A QueryDefs collection contains all QueryDef objects of a Database object in a Microsoft Access database engine database.
Remarks
To create a new QueryDef object, use the CreateQueryDef method. In a Microsoft Access workspace, if you supply a string for the name argument or if you explicitly set the Name property of the new QueryDef object to a non–zero-length string, you will create a permanent QueryDef that will automatically be appended to the QueryDefs collection and saved to disk. Supplying a zero-length string as the name argument or explicitly setting the Name property to a zero-length string will result in a temporary QueryDef object.
To refer to a QueryDef object in a collection by its ordinal number or by its Name property setting, use any of the following syntax forms:
QueryDefs(0)
QueryDefs("name")
QueryDefs![name]
You can refer to temporary QueryDef objects only by the object variables that you have assigned to them.
Methods
Name
| Description
|
|---|
|
| Adds a new QueryDef to the QueryDefs collection.
|
|
| Not supported for this collection.
|
|
| Not supported for this object.
|
Properties
Name
| Description
|
|---|
|
| Returns the number of objects in the specified collection. Read-only.
|
Example
This example creates a new QueryDef object and appends it to the QueryDefs collection of the Northwind Database object. It then enumerates the QueryDefs collection and the Properties collection of the new QueryDef.
Sub QueryDefX()
Dim dbsNorthwind As Database
Dim qdfNew As QueryDef
Dim qdfLoop As QueryDef
Dim prpLoop As Property
Set dbsNorthwind = OpenDatabase("Northwind.mdb")
' Create new QueryDef object. Because it has a
' name, it is automatically appended to the
' QueryDefs collection.
Set qdfNew = dbsNorthwind.CreateQueryDef("NewQueryDef", _
"SELECT * FROM Categories")
With dbsNorthwind
Debug.Print .QueryDefs.Count & _
" QueryDefs in " & .Name
' Enumerate QueryDefs collection.
For Each qdfLoop In .QueryDefs
Debug.Print " " & qdfLoop.Name
Next qdfLoop
With qdfNew
Debug.Print "Properties of " & .Name
' Enumerate Properties collection of new
' QueryDef object.
For Each prpLoop In .Properties
On Error Resume Next
Debug.Print " " & prpLoop.Name & " - " & _
IIf(prpLoop = "", "[empty]", prpLoop)
On Error Goto 0
Next prpLoop
End With
' Delete new QueryDef because this is a
' demonstration.
.QueryDefs.Delete qdfNew.Name
.Close
End With
End Sub
This example uses the CreateQueryDef method to create and execute both a temporary and a permanent QueryDef. The GetrstTemp function is required for this procedure to run.
Sub CreateQueryDefX()
Dim dbsNorthwind As Database
Dim qdfTemp As QueryDef
Dim qdfNew As QueryDef
Set dbsNorthwind = OpenDatabase("Northwind.mdb")
With dbsNorthwind
' Create temporary QueryDef.
Set qdfTemp = .CreateQueryDef("", _
"SELECT * FROM Employees")
' Open Recordset and print report.
GetrstTemp qdfTemp
' Create permanent QueryDef.
Set qdfNew = .CreateQueryDef("NewQueryDef", _
"SELECT * FROM Categories")
' Open Recordset and print report.
GetrstTemp qdfNew
' Delete new QueryDef because this is a demonstration.
.QueryDefs.Delete qdfNew.Name
.Close
End With
End Sub
Function GetrstTemp(qdfTemp As QueryDef)
Dim rstTemp As Recordset
With qdfTemp
Debug.Print .Name
Debug.Print " " & .SQL
' Open Recordset from QueryDef.
Set rstTemp = .OpenRecordset(dbOpenSnapshot)
With rstTemp
' Populate Recordset and print number of records.
.MoveLast
Debug.Print " Number of records = " & _
.RecordCount
Debug.Print
.Close
End With
End With
End Function
The following example shows how to execute a parameter query. The Parameters collection is used to set the Organization parameter of the myActionQuery query before the query is executed.
Public Sub ExecParameterQuery()
Dim dbs As DAO.Database
Dim qdf As DAO.QueryDef
Set dbs = CurrentDb
Set qdf = dbs.QueryDefs("myActionQuery")
'Set the value of the QueryDef's parameter
qdf.Parameters("Organization").Value = "Microsoft"
'Execute the query
qdf.Execute dbFailOnError
'Clean up
qdf.Close
Set qdf = Nothing
Set dbs = Nothing
End Sub
The following example shows how to open a Recordset that is based on a parameter query.
Dim dbs As DAO.Database
Dim qdf As DAO.QueryDef
Dim rst As DAO.Recordset
Set dbs = CurrentDb
'Get the parameter query
Set qfd = dbs.QueryDefs("qryMyParameterQuery")
'Supply the parameter value
qdf.Parameters("EnterStartDate") = Date
qdf.Parameters("EnterEndDate") = Date + 7
'Open a Recordset based on the parameter query
Set rst = qdf.OpenRecordset()