如何从 SQL 填充组合框数据？ 使用 Python

Question

(Picture 1) - Here is the output of my simple program, supposedly it has 5 dropdown items coming from the database but it only displays 1 data which is the last row of the db that has been read.

Picture 1 -

(Picture 2) - Here is the code, I used for loop and I expect it to loop through it and display every data from db but it only display the last row. Is it wrong syntax or wrong logic?

# Combobox - Subjects
self.cbSubjects = ttk.Combobox(root, width=17, textvariable=self.cbSubjects)
self.cbSubjects.place(x=120, y=60)

# SQL Command
self.conn = cx_Oracle.connect('system/system@127.0.0.1/xe')
self.cursor = self.conn.cursor()
self.cursor.execute("SELECT hr.subject.description FROM hr.subject")
for i in self.cursor:

   self.cbSubjects['values'] = (i)
   self.cbSubjects.current(0)

self.cursor.close()
self.conn.close()

(Picture 3) - Here is the SQL data that I'd like to display on my Combobox

Picture 3 -

I'm new to Python tkinter. Thank you so much!

Answer 1

Inside the for loop, you are simply overriding the single value you have in your combobox why this line is executed: self.cbSubjects['values'] = (i) . The last value you assign to it is the last row returned by the SELECT SQL statement. So this is the explanation of the reason you faced that problem.

For the solution, if you take a look at the documentation which is often your best friend, you can read this:

values Specifies the list of values to display in the drop-down listbox.

Actually this is a little bit misleading because self.cbSubjects['values'] is rather a tuple, not a list, and as you know tuples are immutable, unlike lists, but still you can overcome this problem by making making i wearing the clothes of a tuple having one single element.

Maybe with code, you will understand the idea better:

#...
for i in self.cursor:   
   # self.cbSubjects['values'] = (i) , this is bad, change it like this:
   self.cbSubjects['values'] = self.cbSubjects['values'] + (i, )
   # ... rest of your program

Answer 2

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'delivery.ui'
#
# Created by: PyQt5 UI code generator 5.14.1
#
# WARNING! All changes made in this file will be lost!


from PyQt5 import QtCore, QtGui, QtWidgets
import sqlite3
conn = sqlite3.connect("spmanager.db")
cursor = conn.cursor()


class Ui_Form(object):
    def setupUi(self, Form):
        Form.setObjectName("Form")
        Form.resize(773, 621)
        self.label = QtWidgets.QLabel(Form)
        self.label.setGeometry(QtCore.QRect(310, 20, 121, 20))
        font = QtGui.QFont()
        font.setFamily("Ubuntu Condensed")
        font.setPointSize(12)
        font.setBold(True)
        font.setWeight(75)
        self.label.setFont(font)
        self.label.setObjectName("label")
        self.verticalLayoutWidget = QtWidgets.QWidget(Form)
        self.verticalLayoutWidget.setGeometry(QtCore.QRect(50, 210, 701, 331))
        self.verticalLayoutWidget.setObjectName("verticalLayoutWidget")
        self.verticalLayout = QtWidgets.QVBoxLayout(self.verticalLayoutWidget)
        self.verticalLayout.setContentsMargins(0, 0, 0, 0)
        self.verticalLayout.setObjectName("verticalLayout")
        self.tableWidget = QtWidgets.QTableWidget(self.verticalLayoutWidget)
        self.tableWidget.setObjectName("tableWidget")
        self.tableWidget.setColumnCount(3)
        self.tableWidget.setRowCount(1)
        item = QtWidgets.QTableWidgetItem()
        self.tableWidget.setVerticalHeaderItem(0, item)
        item = QtWidgets.QTableWidgetItem()
        self.tableWidget.setHorizontalHeaderItem(0, item)
        item = QtWidgets.QTableWidgetItem()
        self.tableWidget.setHorizontalHeaderItem(1, item)
        item = QtWidgets.QTableWidgetItem()
        self.tableWidget.setHorizontalHeaderItem(2, item)
        self.verticalLayout.addWidget(self.tableWidget)
        self.frame_3 = QtWidgets.QFrame(Form)
        self.frame_3.setGeometry(QtCore.QRect(40, 550, 331, 80))
        self.frame_3.setFrameShape(QtWidgets.QFrame.StyledPanel)
        self.frame_3.setFrameShadow(QtWidgets.QFrame.Raised)
        self.frame_3.setObjectName("frame_3")
        self.label_4 = QtWidgets.QLabel(self.frame_3)
        self.label_4.setGeometry(QtCore.QRect(0, 0, 91, 17))
        self.label_4.setObjectName("label_4")
        self.textEdit = QtWidgets.QTextEdit(self.frame_3)
        self.textEdit.setGeometry(QtCore.QRect(10, 19, 291, 61))
        self.textEdit.setObjectName("textEdit")
        self.layoutWidget = QtWidgets.QWidget(Form)
        self.layoutWidget.setGeometry(QtCore.QRect(50, 70, 691, 91))
        self.layoutWidget.setObjectName("layoutWidget")
        self.gridLayout = QtWidgets.QGridLayout(self.layoutWidget)
        self.gridLayout.setContentsMargins(0, 0, 0, 0)
        self.gridLayout.setObjectName("gridLayout")
        self.frame_2 = QtWidgets.QFrame(self.layoutWidget)
        self.frame_2.setFrameShape(QtWidgets.QFrame.StyledPanel)
        self.frame_2.setFrameShadow(QtWidgets.QFrame.Raised)
        self.frame_2.setObjectName("frame_2")
        self.label_3 = QtWidgets.QLabel(self.frame_2)
        self.label_3.setGeometry(QtCore.QRect(10, 30, 67, 17))
        self.label_3.setObjectName("label_3")
        self.dateEdit = QtWidgets.QDateEdit(self.frame_2)
        self.dateEdit.setGeometry(QtCore.QRect(70, 20, 151, 41))
        self.dateEdit.setObjectName("dateEdit")
        self.gridLayout.addWidget(self.frame_2, 0, 1, 1, 1)
        self.frame = QtWidgets.QFrame(self.layoutWidget)
        self.frame.setFrameShape(QtWidgets.QFrame.StyledPanel)
        self.frame.setFrameShadow(QtWidgets.QFrame.Raised)
        self.frame.setObjectName("frame")
        self.label_2 = QtWidgets.QLabel(self.frame)
        self.label_2.setGeometry(QtCore.QRect(20, 30, 71, 21))
        self.label_2.setObjectName("label_2")
        self.comboBox = QtWidgets.QComboBox(self.frame)
        self.comboBox.setGeometry(QtCore.QRect(80, 30, 171, 25))
        self.comboBox.setEditable(True)
        self.comboBox.setObjectName("comboBox")
        self.comboBox.addItem("")
        #list1 = ['First Item','Second Item','Third Item']
        #self.comboBox.addItems(list1)

        self.gridLayout.addWidget(self.frame, 0, 0, 1, 1)
        self.frame_4 = QtWidgets.QFrame(Form)
        self.frame_4.setGeometry(QtCore.QRect(540, 540, 181, 81))
        self.frame_4.setFrameShape(QtWidgets.QFrame.StyledPanel)
        self.frame_4.setFrameShadow(QtWidgets.QFrame.Raised)
        self.frame_4.setObjectName("frame_4")
        self.comboBox_2 = QtWidgets.QComboBox(self.frame_4)
        self.comboBox_2.setGeometry(QtCore.QRect(5, 20, 141, 25))
        self.comboBox_2.setObjectName("comboBox_2")
        self.comboBox_2.addItem("")
        self.comboBox_2.addItem("")
        self.comboBox_2.addItem("")
        self.comboBox_2.addItem("")
        self.pushButton = QtWidgets.QPushButton(self.frame_4)
        self.pushButton.setGeometry(QtCore.QRect(8, 50, 131, 25))
        self.pushButton.setObjectName("pushButton")

        self.retranslateUi(Form)
        QtCore.QMetaObject.connectSlotsByName(Form)


        def customer_names(self):
            self.conn = conn
            self.cursor = cursor
            self.cursor.execute("SELECT  customer_name FROM customers ORDER BY customer_name")
            self.sql =cursor.fetchall()
        customer_names(self)
        self.names =[]
        for i in self.sql:
            self.names.append(i[0])
        self.comboBox.addItems(self.names)



    def retranslateUi(self, Form):
        _translate = QtCore.QCoreApplication.translate
        Form.setWindowTitle(_translate("Form", "HI-SPECS INNOVATIVE DELIVERY NOTE"))
        self.label.setText(_translate("Form", "DELIVERY NOTE"))
        item = self.tableWidget.verticalHeaderItem(0)
        item.setText(_translate("Form", "1"))
        item = self.tableWidget.horizontalHeaderItem(0)
        item.setText(_translate("Form", "Qnty"))
        item = self.tableWidget.horizontalHeaderItem(1)
        item.setText(_translate("Form", "Item"))
        item = self.tableWidget.horizontalHeaderItem(2)
        item.setText(_translate("Form", "Description"))
        self.label_4.setText(_translate("Form", "Comment"))
        self.label_3.setText(_translate("Form", "Date:"))
        self.label_2.setText(_translate("Form", "Name:"))
        self.comboBox.setItemText(0, _translate("Form", "customer"))
        self.comboBox_2.setItemText(0, _translate("Form", "Print & Record"))
        self.comboBox_2.setItemText(1, _translate("Form", "Print"))
        self.comboBox_2.setItemText(2, _translate("Form", "Record"))
        self.comboBox_2.setItemText(3, _translate("Form", "Email"))
        self.pushButton.setText(_translate("Form", "Continue"))


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    Form = QtWidgets.QWidget()
    ui = Ui_Form()
    ui.setupUi(Form)
    Form.show()
    sys.exit(app.exec_())