[Lazarus] SQLDB: how to use TSQLTransaction

[Michael Van Canneyt]

On Sat, 11 Apr 2015, Xiangrong Fang wrote:

> 2015-04-11 15:41 GMT+08:00 SPRL AFOR <aforsprl at gmail.com>:
>
>       Michael's comments do not need further explanation
>
>       If you want an Sql statement be executed immediately attach an TSqlTransaction to a DB component, attach the TSqlQuery  to the transaction and enclose it between a StartTransaction and a Commit.
>
>       TR.StartTransaction;
>       qr.ExecSql;
>       TR.Commit;
>
>       The Commit matters as well
> 
> 
> ​As a matter of fact, I think yours and Michael's reply both answered part of my questions but not all. I am now clear about the meaning of RowsAffected returning value -1, but I am still not clear about WHY *sometime* I need to
> use Commit, but other times it is *not* necessary?
> 
> If the rule with SQLDB is that I always need to use Commit, fine, I am perfectly fine with this rule.

The rule is: You must *always* use commit.

I cannot explain the behaviour you observed without deeper investigation, but suspect some error in your or sqlite's logic somewhere.
Happens to me also, I think I found a bug, turns out it was me being wrong all along :)

Michael.