QueryDef.SQL property (DAO)
Applies to: Access 2013, Office 2013
Sets or returns the SQL statement that defines the query executed by a QueryDef object.
Syntax
expression .SQL
expression A variable that represents a QueryDef object.
Remarks
The SQL property contains the SQL statement that determines how records are selected, grouped, and ordered when you execute the query. You can use the query to select records to include in a Recordset object. You can also define action queries to modify data without returning records.
The SQL syntax used in a query must conform to the SQL dialect of the query engine, which is determined by the type of workspace. In a Microsoft Access workspace, use the Microsoft Access SQL dialect, unless you create an SQL pass-through query, in which case you should use the dialect of the server.
If the SQL statement includes parameters for the query, you must set these before execution. Until you reset the parameters, the same parameter values are applied each time you execute the query.
In a Microsoft Access workspace, using a QueryDef object is the preferred way to perform SQL pass-through operations on Microsoft Access database engine-connected ODBC data sources. By setting the QueryDef object's Connect property to an ODBC data source, you can use non–Microsoft–Access–database SQL in the query to be passed to the external server. For example, you can use TRANSACT SQL statements (with Microsoft SQL Server or Sybase SQL Server databases), which the Microsoft Access database engine would otherwise not process.
Note
If you set the property to a string concatenated with a non-integer value, and the system parameters specify a non-U.S. decimal character such as a comma (for example, strSQL = "PRICE > " & lngPrice, and lngPrice = 125,50), an error will result when you try to execute the QueryDef object in a Microsoft Access database engine database. This is because during concatenation, the number will be converted to a string using your system's default decimal character, and Microsoft Access SQL only accepts U.S. decimal characters.
Example
This example demonstrates the SQL property by setting and changing the SQL property of a temporary QueryDef and comparing the results. The SQLOutput function is required for this procedure to run.
Sub SQLX()
Dim dbsNorthwind As Database
Dim qdfTemp As QueryDef
Dim rstEmployees As Recordset
Set dbsNorthwind = OpenDatabase("Northwind.mdb")
Set qdfTemp = dbsNorthwind.CreateQueryDef("")
' Open Recordset using temporary QueryDef object and
' print report.
SQLOutput "SELECT * FROM Employees " & _
"WHERE Country = 'USA' " & _
"ORDER BY LastName", qdfTemp
' Open Recordset using temporary QueryDef object and
' print report.
SQLOutput "SELECT * FROM Employees " & _
"WHERE Country = 'UK' " & _
"ORDER BY LastName", qdfTemp
dbsNorthwind.Close
End Sub
Function SQLOutput(strSQL As String, qdfTemp As QueryDef)
Dim rstEmployees As Recordset
' Set SQL property of temporary QueryDef object and open
' a Recordset.
qdfTemp.SQL = strSQL
Set rstEmployees = qdfTemp.OpenRecordset
Debug.Print strSQL
With rstEmployees
' Enumerate Recordset.
Do While Not .EOF
Debug.Print " " & !FirstName & " " & _
!LastName & ", " & !Country
.MoveNext
Loop
.Close
End With
End Function
This example uses the CopyQueryDef method to create a copy of a QueryDef from an existing Recordset and modifies the copy by adding a clause to the SQL property. When you create a permanent QueryDef, spaces, semicolons, or linefeeds may be added to the SQL property; these extra characters must be stripped before any new clauses can be attached to the SQL statement.
Function CopyQueryNew(rstTemp As Recordset, _
strAdd As String) As QueryDef
Dim strSQL As String
Dim strRightSQL As String
Set CopyQueryNew = rstTemp.CopyQueryDef
With CopyQueryNew
' Strip extra characters.
strSQL = .SQL
strRightSQL = Right(strSQL, 1)
Do While strRightSQL = " " Or strRightSQL = ";" Or _
strRightSQL = Chr(10) Or strRightSQL = vbCr
strSQL = Left(strSQL, Len(strSQL) - 1)
strRightSQL = Right(strSQL, 1)
Loop
.SQL = strSQL & strAdd
End With
End Function
This example shows a possible use of CopyQueryNew().
Sub CopyQueryDefX()
Dim dbsNorthwind As Database
Dim qdfEmployees As QueryDef
Dim rstEmployees As Recordset
Dim intCommand As Integer
Dim strOrderBy As String
Dim qdfCopy As QueryDef
Dim rstCopy As Recordset
Set dbsNorthwind = OpenDatabase("Northwind.mdb")
Set qdfEmployees = dbsNorthwind.CreateQueryDef( _
"NewQueryDef", "SELECT FirstName, LastName, " & _
"BirthDate FROM Employees")
Set rstEmployees = qdfEmployees.OpenRecordset( _
dbOpenForwardOnly)
Do While True
intCommand = Val(InputBox( _
"Choose field on which to order a new " & _
"Recordset:" & vbCr & "1 - FirstName" & vbCr & _
"2 - LastName" & vbCr & "3 - BirthDate" & vbCr & _
"[Cancel - exit]"))
Select Case intCommand
Case 1
strOrderBy = " ORDER BY FirstName"
Case 2
strOrderBy = " ORDER BY LastName"
Case 3
strOrderBy = " ORDER BY BirthDate"
Case Else
Exit Do
End Select
Set qdfCopy = CopyQueryNew(rstEmployees, strOrderBy)
Set rstCopy = qdfCopy.OpenRecordset(dbOpenSnapshot, _
dbForwardOnly)
With rstCopy
Do While Not .EOF
Debug.Print !LastName & ", " & !FirstName & _
" - " & !BirthDate
.MoveNext
Loop
.Close
End With
Exit Do
Loop
rstEmployees.Close
' Delete new QueryDef because this is a demonstration.
dbsNorthwind.QueryDefs.Delete qdfEmployees.Name
dbsNorthwind.Close
End Sub
This example uses the CreateQueryDef and OpenRecordset methods and the SQL property to query the table of titles in the Microsoft SQL Server sample database Pubs and return the title and title identifier of the best-selling book. The example then queries the table of authors and instructs the user to send a bonus check to each author based on his or her royalty share (the total bonus is $1,000 and each author should receive a percentage of that amount).
Sub ClientServerX2()
Dim dbsCurrent As Database
Dim qdfBestSellers As QueryDef
Dim qdfBonusEarners As QueryDef
Dim rstTopSeller As Recordset
Dim rstBonusRecipients As Recordset
Dim strAuthorList As String
' Open a database from which QueryDef objects can be
' created.
Set dbsCurrent = OpenDatabase("DB1.mdb")
' Create a temporary QueryDef object to retrieve
' data from a Microsoft SQL Server database.
Set qdfBestSellers = dbsCurrent.CreateQueryDef("")
With qdfBestSellers
' Note: The DSN referenced below must be configured to
' use Microsoft Windows NT Authentication Mode to
' authorize user access to the Microsoft SQL Server.
.Connect = "ODBC;DATABASE=pubs;DSN=Publishers"
.SQL = "SELECT title, title_id FROM titles " & _
"ORDER BY ytd_sales DESC"
Set rstTopSeller = .OpenRecordset()
rstTopSeller.MoveFirst
End With
' Create a temporary QueryDef to retrieve data from
' a Microsoft SQL Server database based on the results from
' the first query.
Set qdfBonusEarners = dbsCurrent.CreateQueryDef("")
With qdfBonusEarners
' Note: The DSN referenced below must be configured to
' use Microsoft Windows NT Authentication Mode to
' authorize user access to the Microsoft SQL Server.
.Connect = "ODBC;DATABASE=pubs;DSN=Publishers"
.SQL = "SELECT * FROM titleauthor " & _
"WHERE title_id = '" & _
rstTopSeller!title_id & "'"
Set rstBonusRecipients = .OpenRecordset()
End With
' Build the output string.
With rstBonusRecipients
Do While Not .EOF
strAuthorList = strAuthorList & " " & _
!au_id & ": $" & (10 * !royaltyper) & vbCr
.MoveNext
Loop
End With
' Display results.
MsgBox "Please send a check to the following " & _
"authors in the amounts shown:" & vbCr & _
strAuthorList & "for outstanding sales of " & _
rstTopSeller!Title & "."
rstTopSeller.Close
dbsCurrent.Close
End Sub
The following example shows how to create a parameter query. A query named myQuery is created with two parameters, named Param1 and Param2. To do this, the SQL property of the query is set to a Structured Query Language (SQL) statement that defines the parameters.
Sample code provided by the Microsoft Access 2010 Programmer’s Reference.
Sub CreateQueryWithParameters()
Dim dbs As DAO.Database
Dim qdf As DAO.QueryDef
Dim strSQL As String
Set dbs = CurrentDb
Set qdf = dbs.CreateQueryDef("myQuery")
Application.RefreshDatabaseWindow
strSQL = "PARAMETERS Param1 TEXT, Param2 INT; "
strSQL = strSQL & "SELECT * FROM [Table1] "
strSQL = strSQL & "WHERE [Field1] = [Param1] AND [Field2] = [Param2];"
qdf.SQL = strSQL
qdf.Close
Set qdf = Nothing
Set dbs = Nothing
End Sub
The following example shows how to replace the Structured Query Language (SQL) statement in a saved query.
Dim qdf as QueryDef
Dim db as Database
Set db = CurrentDB
Set qdf = db.QueryDefs("YourQueryName")
qdf.SQL = ReplaceWhereClause(qdf.SQL, strYourNewWhereClause)
set qdf = Nothing
set db = Nothing
Public Function ReplaceWhereClause(strSQL As Variant, strNewWHERE As Variant)
On Error GoTo Error_Handler
‘This subroutine accepts a valid SQL string and Where clause, and
‘returns the same SQL statement with the original Where clause (if any)
‘replaced by the passed in Where clause.
‘
‘INPUT:
‘ strSQL valid SQL string to change
‘OUTPUT:
‘ strNewWHERE New WHERE clause to insert into SQL statement
‘
Dim strSELECT As String, strWhere As String
Dim strOrderBy As String, strGROUPBY As String, strHAVING As String
Call ParseSQL(strSQL, strSELECT, strWhere, strOrderBy, _
strGROUPBY, strHAVING)
ReplaceWhereClause = strSELECT &""& strNewWHERE &""_
& strGROUPBY &""& strHAVING &""& strOrderBy
Exit_Procedure:
Exit Function
Error_Handler:
MsgBox (Err.Number & ": " & Err.Description)
Resume Exit_Procedure
End Function