pyqt4连接sqlite数据库并通过qtableview显示出来

from PyQt4.QtCore import *
from PyQt4.QtGui import *
from PyQt4.QtSql import *
import sys

db=QSqlDatabase.addDatabase("QSQLITE")
db.setDatabaseName('./a.db')
if db.open():
    print "db is open"
    
class FF(QDialog):
    def __init__(self,parent=None):
         super(FF,self).__init__(parent)
         self.resize(300,300)
         
         self.model=QSqlTableModel(self)
         self.model.setTable("user")
         self.model.setHeaderData(0,Qt.Horizontal,QVariant("xuhao"))
         self.model.setHeaderData(1,Qt.Horizontal,QVariant("content"))
         self.model.select()

         self.view=QTableView(self)
         self.view.resize(300,300)
         self.view.setModel(self.model)
         self.view.resizeColumnsToContents()
         #基类是qmainwindow是用这个方法添加
         #self.setCentralWidget(self.view)
         

         query=QSqlQuery()
         query.exec_("select * from user")
         if query.next():
             print query.value(1).toString()
         

         
app=QApplication(sys.argv)
f=FF()
f.show()
app.exec_()