MySql open doesn't work.

dennis.kim

Hi,

I've seen several docs for mysql in action. But I haven't found a solution on the 3rd day.

Test enviorment>

window 10
Qt 5.13.2
mingw73_64
using mysql-8.0.16 dll

First of all, in code, when database.open is executed, false is returned.

.pro>

QT       += sql

Main.cpp>

#include <QtSql>
#include <QSqlDatabase>

..........................................................................................
    qDebug() << "driverlist " << QSqlDatabase::drivers();

    QSqlDatabase database;
    database = QSqlDatabase::addDatabase("QMYSQL");
    qDebug() << "db connection " << database.open();
-------------------------------------------

result as blow>

driverlist  ("QSQLITE", "QMYSQL", "QMYSQL3", "QODBC", "QODBC3", "QPSQL", "QPSQL7")
QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QODBC QODBC3 QPSQL QPSQL7
db connection  false

I followed the doc below for mysql connection.
https://doc.qt.io/qt-5/sql-driver.html#how-to-build-the-qmysql-plugin-on-windows

I downloaded the mysql zip file. then unzipped.
Some of the tasks listed in the official documentation were executed as follows.

C:\Qt\5.13.2\Src\qtbase\src\plugins\sqldrivers>qmake -version
QMake version 3.1
Using Qt version 5.13.2 in C:/Qt/5.13.2/mingw73_64/lib

C:\Qt\5.13.2\Src\qtbase\src\plugins\sqldrivers>qmake -- MYSQL_INCDIR="C:\mysql-8.0.16-winx64/include" MYSQL_LIBDIR="C:\mysql-8.0.16-winx64/lib"
Info: creating stash file **C:\Qt\5.13.2\Src\qtbase\src\plugins\sqldrivers\.qmake.stash

Running configuration tests...
Checking for DB2 (IBM)... no
Checking for InterBase... no
Checking for MySQL... yes
Checking for OCI (Oracle)... no
Checking for ODBC... yes
Checking for PostgreSQL... no
Checking for SQLite (version 2)... no
Checking for TDS (Sybase)... no
Done running configuration tests.

Configure summary:

Qt Sql Drivers:
  DB2 (IBM) .............................. no
  InterBase .............................. no
  MySql .................................. yes
  OCI (Oracle) ........................... no
  ODBC ................................... yes
  PostgreSQL ............................. no
  SQLite2 ................................ no
  SQLite ................................. yes
    Using system provided SQLite ......... no
  TDS (Sybase) ........................... no

Qt is now configured for building. Just run 'mingw32-make'.
Once everything is built, you must run 'mingw32-make install'.
Qt will be installed into 'C:\Qt\5.13.2\mingw73_64'.

Prior to reconfiguration, make sure you remove any leftovers from
the previous build.

driver install
I copied the libmysql.dll file to the two places below.
C:\Qt\5.13.2\mingw73_64\bin
Where the build exe of the test code is located.

Is there a way to find the cause of the problem or is there any work that is not done yet?

dennis.kim

Finally solved it.

In conclusion, proceed as follows.
Please refer to those who wish.

First, proceed with the basic tasks in the basic document.

Please refer to the site below or what I did in the question I wrote.
https://doc.qt.io/qt-5/sql-driver.html#how-to-build-the-qmysql-plugin-on-windows

And download the appropriate driver from the site below.
I use qt15.3.2, so I downloaded the 15.3.2 driver.
https://github.com/thecodemonkey86/qt_mysql_driver/releases

I pasted the files into the two folders below each.
C:\Qt\5.13.2\mingw73_64\bin
C:\Qt\5.13.2\mingw73_64\plugins\sqldrivers

JonB

@dennis-kim
Just so I understand (I don't use Windows for Qt): why did you need to build a MySQL driver at all from sources, rather than just downloading an already-built version?