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qelectrotech-source-mirror/sources/dataBase/sqlreadonly.h
T
ispyisail 45aec7735b Fix #1045: crash on selecting an element with the online-installer Qt
Since #983, projectDataBase::newQuery() checked a query with
sqlite3_prepare_v2() and sqlite3_stmt_readonly() on the handle of the
QSQLITE driver. Those calls go to the libsqlite3 QElectroTech links. The
QSQLITE plugin of the Qt online installer does not use that library: it
carries its own copy of SQLite, so the handle belongs to another library
and the call crashes. #1021 then put newQuery() on every element
selection, which is where #1045 hits it.

The check now runs the query with PRAGMA query_only set, through the
driver. SQLite refuses a write itself, before touching a row, so the CTE
prefix #983 closed ("WITH x AS (SELECT 1) DELETE FROM element") stays
closed. A refused or failed query comes back empty, because several
callers call exec() again on what newQuery() returns, after query_only
is off.

QElectroTech no longer calls the SQLite C API anywhere.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-09-26 20:06:07 +12:00

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1.4 KiB
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/*
Copyright 2006-2026 The QElectroTech Team
This file is part of QElectroTech.
QElectroTech is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
QElectroTech is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with QElectroTech. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef SQLREADONLY_H
#define SQLREADONLY_H
#include <QSqlDatabase>
#include <QSqlQuery>
#include <QString>
/**
Running a piece of SQL only if it reads.
Deliberately its own translation unit, depending on nothing but Qt SQL:
it is the enforcement point for every query QElectroTech runs against a
project database, including queries that arrive from outside the
application (a .qet file's saved report/table query), so it is worth
being able to test it in isolation -- see
tests/qttest/tst_sqlreadonly.cpp, which links this file and nothing
else of QElectroTech.
*/
namespace QETSql {
QSqlQuery execReadOnly(const QSqlDatabase &db,
const QString &query,
QString *error = nullptr);
}
#endif // SQLREADONLY_H