Selecting data from mysql using qt?

Dii

BTW if you do this, AND it's working, you end up in mysql command line interface, you can get out with 'exit'

doforumda

sorry i couldnt notice Dii user

lyuts

Wow, mysql is full of surprises. Never got those with psql. ¤ Dii ¤, does it have \q command?

doforumda

yes i get into mysql command line

doforumda

whats the reason that my database is not opening in qt?

Dii

lyuts: yes \q is working too

doforumda: ok, so get into the mysql comand line with the command above

/opt/lampp/bin/mysql -D testTwo -h localhost -u root -p

and then do this:

grant all on testTwo.* to 'root'@'localhost' ;

Then we have a working mysql, and the rights are granted, we can get back to your Qt program.

lyuts

I hope the next post will be like "Hooray, I got it working!!!" :)

doforumda

there is an error in sql syntax
@
mysql> grant all on testTwo.* to ‘root’@’localhost’;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '��root’@’localhost’' at line 1
@

Dii

Ok, back to your Qt program:

@#include <QApplication>
#include <QtSql>

int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);

QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
db.setDatabaseName("testTwo");
db.setUserName("root");
db.setPassword("");
db.setHostName("localhost");

bool ok = db.open();
qDebug() << ok;

QSqlQuery query;
query.exec&#40;"SELECT firstname,lastname FROM testTable"&#41;;
while(query.next()) {
    QString firstName = query.value(0).toString();
    QString secondName = query.value(1).toString();
    qDebug() << "First Name: " << firstName << "Last Name:" << secondName;
    qDebug() << db.lastError();
}
return 0;

}@

Notice, we don't set a password here.
The end is 'return 0' instead of 'a.exec()', and it won't hang. The exec() starts the main event loop, and you don't use it here...

lyuts

I think you need to check apostrophes in that command.

Dii

ok, you have wrong apostrof type there. I mean this >> '

doforumda

i tried without apostrophes as well but same error

Dii

nope, you had ` before the root and not '
that was the error

Dii

ok, wait a second, I checked it in the meantime and it won't work without password, stay tuned, I post the right command

doforumda

you mean like this
grant all on testTwo.* to root@localhost ;
if yes it also displaying same error

Dii

so, here we go:

grant all on testTwo.* to 'root'@'localhost' identified by 'password';

Make the right apostrophes! :) You have to set the password in your Qt app too.

Dii

ok, wait I see

Dii

the Devnet's forum motor changes the apostrophes somehow... use the straight apostrophes everywhere
I mean this @'@

doforumda

mysql query did its job its now successful but when i use qt code and try to make it run it displays same error

@
Starting /home/zafar/c++/dbExample-build-desktop/dbExample...
false
QSqlQuery::exec: database not open
/home/zafar/c++/dbExample-build-desktop/dbExample exited with code 0
@

doforumda

wait i think the query is not sucessful because it displays this message 0 rows affected
@
mysql> grant all on testTwo.* to 'root'at'localhost' identified by 'password';
Query OK, 0 rows affected (0.01 sec)
@