ADODB Object

WillExecute

 
Syntax
 
WillExecute Source, CursorType, LockType, Options, adStatus, pCommand, pRecordset, pConnection
Description
This event is called before a pending command is executed.It allows you to change the execution parameters.
The WillExecute event can be fired just before a Command Execute, Connection Execute, or Recordset Open method starts to execute. This event is one of two command execution management events that can be called. The other event is ExecuteComplete.
 
An event is simply a subroutine that can be called automatically after a specific operation has occurred. This subroutine can contain any code that you need to run when the event occurs. The subroutine will only be called if it is included in your code. Future calls to the event subroutine can be cancelled by setting the adStatus parameter to be the adStatusUnwantedEvent constant (see table below) before the event returns.
 
There are eight parameters that are passed to this event.
 
Parameter
Description
Source
The Source parameter is a string that contains either an SQL command or a stored procedure name.
CursorType
The CursorType parameter is a long value that is one of CursorTypeEnum constants.
LockType
The LockType parameter is a long value that is one of LockTypeEnum constants.
Options
The Options parameter is a long value that is one or more of the CommandTypeEnum or ExecuteOptionEnum constants. It comes from the Options parameter of the Command Execute, Connection Execute, or Recordset Open methods.
adStatus
The adStatus parameter defines the status of the event and is set to either the adStatusOK or the adStatusCantDeny values of the EventStatusEnum constants. Before the event returns, to prevent unwanted future firings of this event, set this parameter to adStatusUnwantedEvent, or set it to adStatusCancel to cancel the operation that fired the event.
pCommand
The pCommand parameter is set either to the Command object that was executed or to Nothing.
pRecordset
The pRecordset parameter is set either to the Recordset object that resulted from the execution of the command or to Nothing.
pConnection
The pConnection parameter is the Connection object that is associated with the execution.
 
 
CursorTypeEnum constants 
 
Constant
Value
Description
adOpenDynamic
2
Provides a dynamic cursor
adOpenForwardOnly
0
Default, provides a forward-only cursor
adOpenKeyset
1
Provides a keyset cursor
adOpenStatic
3
Provides a static cursor
adOpenUnpecified
-1
Unspecified
 
 
LockTypeEnum Constants 
 
Constant
Value
Description
adLockBatchOptimistic
4
Multiple users can modify the data and the changes are cached until BatchUpdate is called
adLockOptimistic
3
Multiple users can modify the data which is not locked until Update is called
adLockPessimistic
2
The provider locks each record before and after you edit, and prevents other users from modifying the data
adLockReadOnly
1
Read-only data
adLockUnspecified
-1
Lock type unknown
 
 
CommandTypeEnum Constants 
 
Constant
Value
Description
adCmdFile
256
Evaluate as a previously persisted file
adCmdStoredProc
4
Evaluate as a stored procedure
adCmdTable
2
Have the provider generate a SQL query and return all rows from the specified table
adCmdTableDirect
512
Return all rows from the specified table
adCmdText
1
Evaluate as a textual definition
adCmdUnknown
8
The type of the CommandText parameter is unknown
adCmdUnspecified
-1
Default, does not specify how to evaluate
 
 
ExecuteOptionEnum Constants 
 
Constant
Value
Description
adAsyncExecute
0x10
Execute asynchronously
adAsyncFetch
0x20
Rows beyond the initial quantity specified should be fetched asynchronously
adAsyncFetchNonBlocking
0x40
Records are fetched asynchronously with no blocking of additional operations
adExecuteNoRecords
0x80
Does not return rows and must be combined with adCmdText or adCmdStoredProc
adOptionUnspecified
-1
The option parameter is unspecified
 
 
EventStatusEnum Constants 
 
Constant
Value
Description
adStatusCancel
4
Cancels the operation that fired the event
adStatusCantDeny
3
Cannot cancel pending operation
adStatusErrorsOccurred
2
Indicates that warnings and/or errors occurred
adStatusOK
1
The operation that fired the event was successful
adStatusUnwantedEvent
5
The operation that generated the event cannot generate future events
See Also
Command.Execute, Connection, Execute, Recordset, Recordset.Open.
Example
 
' Use the WithEvents keyword to designate that events
' can be handled by this Connection object
Dim WithEvents objConn As ADODB.Connection
 
' Note how the object name, objConn, is incorporated into the event Sub name
Private Sub objConn_WillExecute( Source As String, _
   CursorType As ADODB.CursorTypeEnum, _
   LockType As ADODB.LockTypeEnum, _
   Options As Long _
   adStatus As ADODB.EventStatusEnum, _
   ByVal pCommand As ADODB.Command , _
   ByVal pRecordset As ADODB.Recordset , _
   ByVal pConnection As ADODB.Connection )
 
' place any code you desire here, for example
If LockType = adLockReadOnly Then
   Print "The Lock Type is read-only"
End If
 
End Sub