[Gambas-user] [Gambas Bug Tracker] Bug #1113: ODBC driver problem: driver connects but does not exec query

[bugtracker at ...3416...]

http://gambaswiki.org/bugtracker/edit?object=BUG.1113&from=L21haW4-

Comment #13 by PICCORO LENZ MCKAY:

i think your patch are not so "ugly" due relies on the bad behaviour of the ODBC and SQL standar, i mean umm jajaja its very confusing that the ODBC paper said after a "susessfull sql ddl" return SQL_NO_DATA event SQL_SUCCESS, but with M$ behind scenes.. no surprises..

analizing, if the SQL running was successfully and its no a SQL DML must retrieve as response SQL_SUCCESS, the problem maybe are on that cases:

UPDATE, DELETE and INSERT does not retrieve any rows, only notifies was afected rows.. so return a SQL_NO_DATA, but are DML, so the only case that return data its the SELECT case... so we can assume that any other statement will no return never some data.. only "affected rows" so for any SQL query made, we can assumed SQL_SUCCESS if no problem was happened.. the only exception will be SELECT and for those are not usefully due we not have proper CURSOR, only a FORWARD ONLY cursor...

due that explanation, i think the only you can do its to assume that behaviour of the "ugly patch", so or SQL_SUCCESS or not...


as a informative for others, SQL querys can be divided into two parts: The Data Manipulation Language (DML) querys and the Data Definition Language (DDL) querys

CAUTION: in the stupid mysql and sqlite, the ALTER query has a "afected rows" behavior due some info are stored on tables...

EXAMPLES OF SQL DML:

SELECT – this retriebve data always or not
UPDATE – not retrieve data, only "affected rows"
DELETE – not retrieve data, only "affected rows"
INSERT INTO – not retrieve data, only "affected rows"

EXAMPLES OF SQL DDL:

CREATE DATABASE – no any data, only "succesfull or not"
ALTER DATABASE – no any data, only "succesfull or not"
CREATE TABLE – no any data, only "succesfull or not"
ALTER TABLE – no any data, only "succesfull or not"
DROP TABLE – no any data, only "succesfull or not"
CREATE INDEX – crea un índice.
DROP INDEX – borra un índice.

PICCORO LENZ MCKAY changed the state of the bug to: Accepted.