Hi,
what is the correct method to retreive last inserted GUID from a table (defined as Default CURRENT_GUID)?
Until now I used
Table.Append()
Table.FieldByName= ...
Table.FieldByName= ...
Table.Post()
myGUID= Table.FieldByName("GUID")->AsString
but sometime i receive a NULL value and other time a wrong value.
Now I use
Table.Append()
myGUID= Table.FieldByName("GUID")->AsString
Table.FieldByName= ...
Table.FieldByName= ...
Table.Post()
and seem ok.
What is the correct way?

Thanks!
Mirco

Mirco


You need to use SQL and check the LASTIDENTITY (Secion 9.14) in my pdf manual

Example from the manual

SELECT LASTIDENTITY('Customer', 'CustNo') AS LastCustNo

Roy Lambert

Roy Lambert wrote:

Mirco


You need to use SQL and check the LASTIDENTITY (Secion 9.14) in my pdf manual

Example from the manual

SELECT LASTIDENTITY('Customer', 'CustNo') AS LastCustNo

Roy Lambert


Sorry but the field is definited as GUID, the LASTIDENTITY for me always return 0
This is the table definition
"CREATE TABLE "giri"
(
"idx" GUID COLLATE "UNI" DEFAULT CURRENT_GUID NOT NULL,
"prog" INTEGER NOT NULL, ...
)

Mirco


I apologise. I should have remembered this from a previous thread, especially since I was involved in it. I have an idea which if it works will take me a little time to work out.

Roy Lambert

Mirco


This query

SELECT
idx
FROM
giri
ORDER BY __RowID DESC
RANGE 1 to 1

will give you what you want (I hope)


Roy Lambert

Thanks for the reply.
This seems to work but doing a query after the insert slows down the work for me a lot (in some situations I have to insert several thousand records and the work doubles).
In a short test the query takes 60mS in my table.
It just seemed strange to me that there wasn't a method like the OUT parameter that can be used in scripts.

Thanks!
Mirco

Mirco

>This seems to work but doing a query after the insert slows down the work for me a lot (in some situations I have to insert several thousand records and the work doubles).
>It just seemed strange to me that there wasn't a method like the OUT parameter that can be used in scripts.

Are you using SQL for the insert? If so it should be possible to use an OUT (or an inout) parameter. My aging memory tells me there's something about that on these ngs. If you're using SQL I'll see if I can track it down.

Out of interest why do you want to get the GUID after insert? If its to create a linked table you might be better off using an after insert trigger.

Roy

No unfortunately I have to use a table with Append () to insert the new record.
I need the GUID to update 2 other linked tables

In the meantime i am trying with Sysutils::CreateGUID() which seems to work for the same purpose.
Any contraindications to this method?
Thanks!

Mirco


>In the meantime i am trying with Sysutils::CreateGUID() which seems to work for the same purpose.
>Any contraindications to this method?
>Thanks!

As long as you remove the default from idx you should be fine.

Roy