asked on

Working with StartTransaction ???

How can I use correctly StartTransaction ?

I have this :
( Query1.CachedUpdate := True )

Database1.Open ;
Database1.StartTransaction ;

With Query1, Sql Do
Begin
Close ;
Clear ;
Add('INSERT INTO Test') ;
Add('VALUES (:Username, :LongName)') ;
ParamByName('Username').AsString := 'Toto' ;
ParamByName('Longname').AsString := 'Grand Toto' ;
ExecSql ;
End ;

Query1.ApplyUpdates ;
Database1.Commit ;
Query1.CommitUpdates ;

But when I run it, I have and error messsage on Query1.ApplyUpdates :
"Dataset not in edit or insert mode."

What can I do ?
Thanks

ASKER CERTIFIED SOLUTION

excalibur256

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geobul

Hi,
I'm not sure but try this:

Database1.Open ;

With Query1, Sql Do
Begin
Close ;
Clear ;
Add('INSERT INTO Test') ;
Add('VALUES (:Username, :LongName)') ;
ParamByName('Username').AsString := 'Toto' ;
ParamByName('Longname').AsString := 'Grand Toto' ;
ExecSql ;
end;

if Query1.UpdatesPending then
Database1.ApplyUpdates([Query1]);
End ;

Regards, Geo

kretzschmar

i guess cached updates are only usefull with an select-query,

you get the error because you don't call query.edit or query.insert,
which may cause a dataset not open error, because you can't open a insert query

if you want the capability of cached updates, then use a select-query,
open the query,
insert your new records with the insert method,
supply your fieldvalues with query.fielsbyname().as.. := whatever
post the insert and
start again with a new record,
if you are ready then you do a applyupdate

meikl ;-)

geobul

Hi,
Using my solution you don't need to think what the query does (select, insert, etc.) because you check for pending updates first.
The second thing is that TDatabase.ApplyUpdates does all the transaction stuff internally (starts a transaction, commits or rolls back and clears the updates cache) for you.

Regards, Geo