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Ross Wise · Guest

Hey!

How do I write and attach an event handler to an un-published (doesn't show on object inspector) event?

Specifically in D7 connected to IB6.5

I am trying to trap for an EDatabaseError exception on a TSQLDataSet.

A Try..Execpt block doesn't work; appareantly because the component has handled the exception by the time it would fall through
to the except block. I assume that I need to write an OnPostError event handler but that is not a published event.

How do I do this, or is there an easier way?

Ross
WEAVE, Inc.
Sacramento, CA

Wayne Niddery [TeamB] · Guest

Ross Wise wrote:

Bill Todd (TeamB) · Guest

Since TSQLDataSet is read only it is not possible to generate an
OnPostError event. That is why the event is not published. To update
data returned by TSQLDataSet interactively you must use a
DataSetProvider and TClientDataSet. Errors will be returned through
the ClientDataSet's OnReconcileError event handler.

--
Bill (TeamB)
(TeamB cannot respond to questions received via email)

Ross Wise · Guest

Wayne,

Thanks for replying, the code is below:

Bill,

Thanks for replying. I'm not trying to update data returned, I'm executing an INSERT statement.

This is the Statement in the tSQLDataSet "sqldsV_InsertPhoneNumbers"
INSERT INTO DX_PHONE_NUMBERS
VALUES ( :ClientID,
:PhoneID,
:AreaCode,
:PhoneNumber,
:Extension,
:CallingRule ) ;

The primary key on DX_PHONE_NUMBERS is (ClientID+PhoneID), I am trying to capture a "PRIMARY or UNIQUE KEY constraint" exception.

Here is the code, the MessageDlg statement is never executed, an EDatabaseError halts the program:

:
:
then with cDemogRec.PH_Numbers[loopCount]
{with} do begin

sqldsV_InsertPhoneNumbers.close ;

sqldsV_InsertPhoneNumbers.ParamByName('ClientID').AsInteger := cDemogRec.ClientID ;
if Phone_ID <> ''
then sqldsV_InsertPhoneNumbers.ParamByName('PhoneID').AsString := Phone_ID
else sqldsV_InsertPhoneNumbers.ParamByName('PhoneID').AsString := 'Phone#'+IntToStr(loopCount) ;

sqldsV_InsertPhoneNumbers.ParamByName('AreaCode').AsString := Phone_AreaCode ;
sqldsV_InsertPhoneNumbers.ParamByName('PhoneNumber').AsString := Phone_Number ;
sqldsV_InsertPhoneNumbers.ParamByName('Extension').AsString := '' ;
sqldsV_InsertPhoneNumbers.ParamByName('CallingRule').AsString := Phone_CallingRule ;

try

sqldsV_InsertPhoneNumbers.ExecSQL ;

except

on E: EDataBaseError
{exception} do begin

MessageDlg('Exception Encountered...',mtInformation,[mbOK],0) ;

ShowException(E,Addr(E)) ;

{exception} end ;

{try} end ;

{with} end ;
:
:

Wayne Niddery [TeamB] wrote:

Wayne Niddery [TeamB] · Guest

Ross Wise wrote:

Ross Wise · Guest

Wayne,

I found out what was happening. The Debugger was capturing the error!

Running the application outside the IDE or with the debugger instructed to ignore EDatabaseError exceptions, the code works as
expected.

Now, a new question: Identifying a Duplicate Key error as opposed to some other error:
This works:

ErrorCondition := E.Message ;
if pos('PRIMARY or UNIQUE KEY constraint',ErrorCondition) > 0
then MessageDlg('Duplicate Key Encountered',mtInformation,[mbOK],0)
else ShowException(E,Addr(E)) ;

But seems somewhat unreliable since it depends on the error string remaining exactly the same. Is there another property or
method for identifying error 'sub-types'?

Ross Wise
WEAVE, Inc.
Sacramento, CA

Wayne Niddery [TeamB] wrote: