Database.Execute Method (DAO)
Runs an action query or executes an SQL statement on the specified object.
Syntax
expression .Execute(Query, Options)
expression A variable that represents a Database object.
Parameters
Name |
Required/Optional |
Data Type |
Description |
|---|---|---|---|
Query |
Required |
String |
|
Options |
Optional |
Variant |
Remarks
You can use the following **RecordsetOptionEnum**constants for options.
Constant |
Description |
|---|---|
dbDenyWrite |
Denies write permission to other users (Microsoft Access workspaces only). |
dbInconsistent |
(Default) Executes inconsistent updates (Microsoft Access workspaces only). |
dbConsistent |
Executes consistent updates (Microsoft Access workspaces only). |
dbSQLPassThrough |
Executes an SQL pass-through query. Setting this option passes the SQL statement to an ODBC database for processing (Microsoft Access workspaces only). |
dbFailOnError |
Rolls back updates if an error occurs (Microsoft Access workspaces only). |
dbSeeChanges |
Generates a run-time error if another user is changing data you are editing (Microsoft Access workspaces only). |
dbRunAsync |
Executes the query asynchronously (ODBCDirect Connection and QueryDef objects only). |
dbExecDirect |
Executes the statement without first calling SQLPrepare ODBC API function (ODBCDirect Connection and QueryDef objects only). |
Note
ODBCDirect workspaces are not supported in Microsoft Access 2010. Use ADO if you want to access external data sources without using the Microsoft Access database engine.
Note
The constants dbConsistent and dbInconsistent are mutually exclusive. You can use one or the other, but not both in a given instance of OpenRecordset. Using both dbConsistent and dbInconsistent causes an error.
The Execute method is valid only for action queries. If you use Execute with another type of query, an error occurs. Because an action query doesn't return any records, Execute doesn't return a Recordset. (Executing an SQL pass-through query in an ODBCDirect workspace will not return an error if a Recordset isn't returned.)
Use the RecordsAffected property of the Connection, Database, or QueryDef object to determine the number of records affected by the most recent Execute method. For example, RecordsAffected contains the number of records deleted, updated, or inserted when executing an action query. When you use the Execute method to run a query, the RecordsAffected property of the QueryDef object is set to the number of records affected.
In a Microsoft Access workspace, if you provide a syntactically correct SQL statement and have the appropriate permissions, the Execute method won't fail — even if not a single row can be modified or deleted. Therefore, always use the dbFailOnError option when using the Execute method to run an update or delete query. This option generates a run-time error and rolls back all successful changes if any of the records affected are locked and can't be updated or deleted.
In earlier versions of the Microsoft Jet database engine, SQL statements were automatically embedded in implicit transactions. If part of a statement executed with dbFailOnError failed, the entire statement would be rolled back. To improve performance, these implicit transactions were removed starting with version 3.5. If you are updating older DAO code, be sure to consider using explicit transactions around Execute statements.
For best performance in a Microsoft Access workspace, especially in a multiuser environment, nest the Execute method inside a transaction. Use the BeginTrans method on the current Workspace object, then use the Execute method, and complete the transaction by using the CommitTrans method on the Workspace. This saves changes on disk and frees any locks placed while the query is running.
Example
This example demonstrates the Execute method when run from both a QueryDef object and a Database object. The ExecuteQueryDef and PrintOutput procedures are required for this procedure to run.
Sub ExecuteX()
Dim dbsNorthwind As Database
Dim strSQLChange As String
Dim strSQLRestore As String
Dim qdfChange As QueryDef
Dim rstEmployees As Recordset
Dim errLoop As Error
' Define two SQL statements for action queries.
strSQLChange = "UPDATE Employees SET Country = " & _
"'United States' WHERE Country = 'USA'"
strSQLRestore = "UPDATE Employees SET Country = " & _
"'USA' WHERE Country = 'United States'"
Set dbsNorthwind = OpenDatabase("Northwind.mdb")
' Create temporary QueryDef object.
Set qdfChange = dbsNorthwind.CreateQueryDef("", _
strSQLChange)
Set rstEmployees = dbsNorthwind.OpenRecordset( _
"SELECT LastName, Country FROM Employees", _
dbOpenForwardOnly)
' Print report of original data.
Debug.Print _
"Data in Employees table before executing the query"
PrintOutput rstEmployees
' Run temporary QueryDef.
ExecuteQueryDef qdfChange, rstEmployees
' Print report of new data.
Debug.Print _
"Data in Employees table after executing the query"
PrintOutput rstEmployees
' Run action query to restore data. Trap for errors,
' checking the Errors collection if necessary.
On Error GoTo Err_Execute
dbsNorthwind.Execute strSQLRestore, dbFailOnError
On Error GoTo 0
' Retrieve the current data by requerying the recordset.
rstEmployees.Requery
' Print report of restored data.
Debug.Print "Data after executing the query " & _
"to restore the original information"
PrintOutput rstEmployees
rstEmployees.Close
Exit Sub
Err_Execute:
' Notify user of any errors that result from
' executing the query.
If DBEngine.Errors.Count > 0 Then
For Each errLoop In DBEngine.Errors
MsgBox "Error number: " & errLoop.Number & vbCr & _
errLoop.Description
Next errLoop
End If
Resume Next
End Sub
Sub ExecuteQueryDef(qdfTemp As QueryDef, _
rstTemp As Recordset)
Dim errLoop As Error
' Run the specified QueryDef object. Trap for errors,
' checking the Errors collection if necessary.
On Error GoTo Err_Execute
qdfTemp.Execute dbFailOnError
On Error GoTo 0
' Retrieve the current data by requerying the recordset.
rstTemp.Requery
Exit Sub
Err_Execute:
' Notify user of any errors that result from
' executing the query.
If DBEngine.Errors.Count > 0 Then
For Each errLoop In DBEngine.Errors
MsgBox "Error number: " & errLoop.Number & vbCr & _
errLoop.Description
Next errLoop
End If
Resume Next
End Sub
Sub PrintOutput(rstTemp As Recordset)
' Enumerate Recordset.
Do While Not rstTemp.EOF
Debug.Print " " & rstTemp!LastName & _
", " & rstTemp!Country
rstTemp.MoveNext
Loop
End Sub