Selecting data from mysql using qt?

Dii

db.lasterror().text() should come after line 16 (db.open()).
The password in the Qt code must be the same what you have specified in the GRANT command above.

I suspect probably, you haven't made the database and the table in mysql yet, if you go back to mysql command line, what do you get by these commands:

@SHOW databases;

USE testTwo;

SHOW tables;@

I go to dinner, be back in a few minutes :)

lyuts

You put my debug before opening the connection. Put it after.

doforumda

i changed db.lastError().text(); and place it after db.open()
this is the output
@
Starting /home/zafar/c++/dbExample-build-desktop/dbExample...
"Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2) QMYSQL: Unable to connect"
false
QSqlQuery::exec: database not open
/home/zafar/c++/dbExample-build-desktop/dbExample exited with code 0
@

the commands in mysql displayed are here
repectively to your commands

mysql> use testTwo
Database changed
mysql> show tables
-> ;
+-------------------+
| Tables_in_testTwo |
+-------------------+
| testTable |
+-------------------+
1 row in set (0.01 sec)

@

doforumda

any clues?

lyuts

Change the 19th line to

@QSqlQuery query(db);@

doforumda

same error again

lyuts

Take a look into mysql logs to see what happens when you are trying to connect from your application.

doforumda

how can i check that mysql logs and from where?

lyuts

[quote author="doforumda" date="1286880547"]how can i check that mysql logs and from where? [/quote]

Try to find them:
@find /opt/lampp -name log -type d@

When you find the log directory, find a log for mysql and use tail utility:

@tail -f /path/to/mysql.log@

doforumda

this command didnt return something
@
root@zafar-laptop:/# find /opt/lampp -name log -type d
root@zafar-laptop:/#
@

doforumda

i have a folder inside lampp with the name logs. is it the one which your are talking about

lyuts

Solution 1:
@find /opt/lampp -name '*.log'@
This might need sudo'ing.

Solution 2:
If 1st fails then you need to find the config files for mysql (it should be located in /opt/lampp directory) and try to find out what is the location of mysql's log files.

doforumda

there are 6 files in there but no mysql.log

these are the files
access_log, cgisock.1693, error_log, httpd.pid, php_error_log, ssl_request_log

Dii

Don't bother with the log files, I guess Qt looks at the wrong place for the socket file...

Let's check this line in your mysql config file (my.cnf):

socket = /var/run/mysqld/mysqld.sock

You should find my.cnf in /etc/ or /etc/mysql/ ... I don't know ubuntu that much.

doforumda

1st solution returns this
@
root@zafar-laptop:/# find /opt/lampp -name *.log
/opt/lampp/htdocs/xampp/contrib/sqlnet.log
@

doforumda

with which editor i can view that .conf file. with gedit or something.

lyuts

[quote author="¤ Dii ¤" date="1286881470"]
You should find my.cnf in /etc/ or /etc/mysql/ ... I don't know ubuntu that much.[/quote]

I don't think that this config will be in /etc. He uses lampp - a preconfigured bundle. That config might be in /opt/lampp.

Dii

BTW a quick sum:

mysql is installed
database and tables are created
access is granted
qt code looks fine

I see two possibilities here: libmysqlclient is missing, or the socket file is at different place.

doforumda

the file my.cnf is in etc/mysql folder

Dii

doforumda: use gedit

sudo gedit /etc/mysql/my.cnf

at least most of the ubuntu machines have the config file there.