QueryDefs collection (DAO)

Applies to: Access 2013, Office 2013

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.

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.

Sample code provided by the Microsoft Access 2010 Programmer’s Reference.

    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()