TDBGrid is not updating record
lazarus / 16-Databases

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vfclists · 2009-03-27 09:08

I am just trying out Lazarus and its Database components, and I have
add all the necessary components to link to the database and the
records are showing in the grid.

However all though new records and updated records show in the grid,
they are not updated into the database.

Are there some additional stuff to do - I thought they would work like
in Delphi?

Are there some samples, showing how it works?

Is it necessary to modify the Insert, Update, and DeleteSQL
properties, and make some changes in the Transaction component to get
it work.

I would like some links to examples please.


Thx

Frank

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Loesje · 2009-03-27 13:00

You provided way too less information. "all the necessary components"
We'll see about that.

But I'm in a goo mood so I'll guess around. First guess: You used the
TSQLQuery from Sqldb. Second guess: you used a database which uses
transactions (Firebird, PostgreSQL) and forgot to commit the
transaction. (TSQLTransaction.Commit) So the changes thrown away when
your application quits.

Third guess: You forgot to call TSQLQuery.ApplyUpdates to store the
changes in the database at all.

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vfclists · 2009-03-31 08:35

Quote from: Loesje on March 27, 2009, 02:00:34 pmYou provided way too
less information. "all the necessary components" We'll see about that.

But I'm in a goo mood so I'll guess around. First guess: You used the
TSQLQuery from Sqldb. Second guess: you used a database which uses
transactions (Firebird, PostgreSQL) and forgot to commit the
transaction. (TSQLTransaction.Commit) So the changes thrown away when
your application quits.

Third guess: You forgot to call TSQLQuery.ApplyUpdates to store the
changes in the database at all.


1. All the necessary components are there, Connection, Query and
Transaction components, DataSource and Grid are all present and linked
up.

2. I am connecting to a MySQL database

3. The UpdateSQL, InsertSQL and DeleteSQL settings are not set, which
I believe is not necessary unless is is a join query. This is a
straight select query from a table with a primary key.

4. If I am to use ApplyUpdates, which event should they be attached
to.

I think docs are what I need, but the wiki is rather skimpy.

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Loesje · 2009-03-31 10:43

There are no connection, query and transaction components in Lazarus.
So I still don't know which components you used. (There is, for
example a TSQLQuery component. Did you use that?)

And you can call applyupdates at any moment you want. One idea would
be to add a 'save' button, for example.

Or when you close the window.

Or when you scroll to another record.

But that's up to you to decide

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vfclists · 2009-03-31 12:12

I got it working after adding code to the InsertSQL, DeleteSQL and
UpdateSQL properties, and by calling ApplyUpdates in the AfterPost
event.

Quote from: Loesje on March 31, 2009, 12:43:41 pmThere are no
connection, query and transaction components in Lazarus. So I still
don't know which components you used. (There is, for example a
TSQLQuery component. Did you use that?)

And you can call applyupdates at any moment you want. One idea would
be to add a 'save' button, for example.

Or when you close the window.

Or when you scroll to another record.

But that's up to you to decide