PyQt5

Hej
Czy możecie mi pomóc?? Mam taki kod:

from PyQt5 import QtCore, QtGui, QtWidgets
import pymysql
 
 
 
class Ui_MainWindow(object):
 
    def LoadData(self):
        conn = pymysql.connect(host="106.90.5.2",user="admin",password="admin123",db="pyqt5")
         
        with conn:
            myCursor=conn.cursor()
            cur = conn.cursor()
            cur.execute("select * from data ")
 
            for i in range(cur.rowcount):
                result=cur.fetchall()
 
                for row in result:
                    self.cursor=QTextCursor(self.a1.document())
 
                    self.cursor.insertText(str(row[1]+"\n"))
     
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(845, 600)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.a1 = QtWidgets.QLineEdit(self.centralwidget)
        self.a1.setGeometry(QtCore.QRect(10, 20, 211, 20))
        self.a1.setObjectName("a1")
        self.a2 = QtWidgets.QLineEdit(self.centralwidget)
        self.a2.setGeometry(QtCore.QRect(10, 50, 211, 20))
        self.a2.setObjectName("a2")
        self.b1 = QtWidgets.QLineEdit(self.centralwidget)
        self.b1.setGeometry(QtCore.QRect(230, 20, 171, 20))
        self.b1.setObjectName("b1")
        self.b2 = QtWidgets.QLineEdit(self.centralwidget)
        self.b2.setGeometry(QtCore.QRect(230, 50, 171, 20))
        self.b2.setObjectName("b2")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 845, 21))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)
 
        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)
 
    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
 
 
if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

chciałbym, aby po wpisaniu w b1 = QtWidgets.QLineEdit przeszukało moją bazę danych mysql i wynik wstawiło do wartości a1 = QtWidgets.QLineEdit zapytanie SQL, powinno uruchamiać się po wpisaniu 9 znaków w b1, czy możecie mi pomóc ?