TRANSFORM Statement (Microsoft Access SQL)

Access Developer Reference

Creates a crosstab query.

Syntax

TRANSFORM aggfunction     selectstatement     PIVOT pivotfield [IN (value1[, value2[, …]])]

The TRANSFORM statement has these parts:

Part Description
aggfunction An SQL aggregate function that operates on the selected data.
selectstatement A SELECT statement.
pivotfield The field or expression you want to use to create column headings in the query's result set.
value1, value2 Fixed values used to create column headings.
Remarks

When you summarize data using a crosstab query, you select values from specified fields or expressions as column headings so you can view data in a more compact format than with a select query.

TRANSFORM is optional but when included is the first statement in an SQL string. It precedes a SELECT statement that specifies the fields used as row headings and a GROUP BY clause that specifies row grouping. Optionally, you can include other clauses, such as WHERE, that specify additional selection or sorting criteria. You can also use subqueries as predicates — specifically, those in the WHERE clause — in a crosstab query.

The values returned in pivotfield are used as column headings in the query's result set. For example, pivoting the sales figures on the month of the sale in a crosstab query would create 12 columns. You can restrict pivotfield to create headings from fixed values (value1, value2 ) listed in the optional IN clause. You can also include fixed values for which no data exists to create additional columns.

Example

This example uses the SQL TRANSFORM clause to create a crosstab query showing the number of orders taken by each employee for each calendar quarter of 1994. The SQLTRANSFORMOutput function is required for this procedure to run.

  Sub TransformX1()
Dim dbs As Database
Dim strSQL As String
Dim qdfTRANSFORM As QueryDef

strSQL = "PARAMETERS prmYear SHORT; TRANSFORM " _
    & "Count(OrderID) " _
    & "SELECT FirstName & "" "" & LastName AS " _
    & "FullName FROM Employees INNER JOIN Orders " _
    & "ON Employees.EmployeeID = " _
    & "Orders.EmployeeID WHERE DatePart " _
    & "(""yyyy"", OrderDate) = [prmYear] "

   strSQL = strSQL & "GROUP BY FirstName & " _
    & """ "" & LastName " _
    & "ORDER BY FirstName & "" "" & LastName " _
    & "PIVOT DatePart(""q"", OrderDate)"

' Modify this line to include the path to Northwind
' on your computer.
Set dbs = OpenDatabase("Northwind.mdb")

Set qdfTRANSFORM = dbs.CreateQueryDef _
    ("", strSQL)

SQLTRANSFORMOutput qdfTRANSFORM, 1994

dbs.Close

End Sub

This example uses the SQL TRANSFORM clause to create a slightly more complex crosstab query showing the total dollar amount of orders taken by each employee for each calendar quarter of 1994. The SQLTRANSFORMOutput function is required for this procedure to run.

  Sub TransformX2()
Dim dbs As Database
Dim strSQL As String
Dim qdfTRANSFORM As QueryDef

strSQL = "PARAMETERS prmYear SMALLINT; TRANSFORM " _
    & "Sum(Subtotal) SELECT FirstName & "" """ _
    & "& LastName AS FullName " _
    & "FROM Employees INNER JOIN " _
    & "(Orders INNER JOIN [Order Subtotals] " _
    & "ON Orders.OrderID = " _
    & "[Order Subtotals].OrderID) " _
    & "ON Employees.EmployeeID = " _
    & "Orders.EmployeeID WHERE DatePart" _
    & "(""yyyy"", OrderDate) = [prmYear] "

   strSQL = strSQL & "GROUP BY FirstName & "" """ _
    & "& LastName " _
    & "ORDER BY FirstName & "" "" & LastName " _
    & "PIVOT DatePart(""q"",OrderDate)"        
    
' Modify this line to include the path to Northwind
' on your computer.
Set dbs = OpenDatabase("Northwind.mdb")

Set qdfTRANSFORM = dbs.CreateQueryDef _
    ("", strSQL)

SQLTRANSFORMOutput qdfTRANSFORM, 1994

dbs.Close

End Sub

Function SQLTRANSFORMOutput(qdfTemp As QueryDef, _ intYear As Integer)

Dim rstTRANSFORM As Recordset
Dim fldLoop As Field
Dim booFirst As Boolean

qdfTemp.PARAMETERS!prmYear = intYear
Set rstTRANSFORM = qdfTemp.OpenRecordset()

Debug.Print qdfTemp.SQL
Debug.Print
Debug.Print , , "Quarter"

With rstTRANSFORM
    booFirst = True
    For Each fldLoop In .Fields
        If booFirst = True Then
            Debug.Print fldLoop.Name
            Debug.Print , ;
            booFirst = False
        Else
            Debug.Print , fldLoop.Name;
        End If
    Next fldLoop
    Debug.Print
    
    Do While Not .EOF
        booFirst = True
        For Each fldLoop In .Fields
            If booFirst = True Then
                Debug.Print fldLoop
                Debug.Print , ;
                booFirst = False
            Else
                Debug.Print , fldLoop;
            End If
        Next fldLoop
        Debug.Print
        .MoveNext
    Loop
End With

End Function

See Also

FROM Clause (Microsoft Access SQL)

GROUP BY Clause (Microsoft Access SQL)

INNER JOIN Operation (Microsoft Access SQL)

ORDER BY Clause (Microsoft Access SQL)

SELECT Statement (Microsoft Access SQL)

SQL Aggregate Functions (SQL)

SQL Subqueries

WHERE Clause (Microsoft Access SQL)