while running my qt code

Running build steps for project qbank...
Configuration unchanged, skipping QMake step.
Starting: /usr/bin/make debug -w
make: Entering directory `/home/tts/Desktop/QbankEditorAllrequirement'
/usr/bin/make -f Makefile.Debug
make[1]: Entering directory `/home/tts/Desktop/QbankEditorAllrequirement'
make[1]: Nothing to be done for `first'.
make[1]: Leaving directory `/home/tts/Desktop/QbankEditorAllrequirement'
make: Leaving directory `/home/tts/Desktop/QbankEditorAllrequirement'
Exited with code 0.

i'm working in qt4.

Running build steps for project qbank...
Configuration unchanged, skipping QMake step.
Starting: /usr/bin/make debug -w
make: Entering directory `/home/tts/Desktop/QbankEditorAllrequirement'
/usr/bin/make -f Makefile.Debug
make[1]: Entering directory `/home/tts/Desktop/QbankEditorAllrequirement'
make[1]: Nothing to be done for `first'.
make[1]: Leaving directory `/home/tts/Desktop/QbankEditorAllrequirement'
make: Leaving directory `/home/tts/Desktop/QbankEditorAllrequirement'
Exited with code 0.

while commiting to db i get the exit status as,

ASSERT: "i >= 0" in file /usr/include/qt4/QtCore/qstring.h, line 875
The program has unexpectedly finished.
/home/tts/Desktop/QbankEditorAllrequirement/qbank exited with code 0

when i debug my code

"The inferior stopped because it received a signal from the Operating system
Signal name : SIGABRT
Signal meaning : SignalAborting"

when i click ok,
it shows the error in my commit.cpp file,
in while loop.
any1 knows wat the error might be.please help me