将lineEdit输入插入数据库时 ，PyQt5.QtSql.QSqlError

Question

我想将QLineEdit输入插入数据库

import sys
from PyQt5 import QtWidgets as qtw
from PyQt5 import QtCore as qtc
from PyQt5 import QtGui as qtg

from PyQt5 import QtSql as qsql


class Secondwindow(qtw.QWidget):
    '''
    description einfügen
    '''

    # Attribut Signal

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        # your code will go here

        # Messung starten
        self.connectdb_button = qtw.QPushButton("Connect to Database ?")
        hlaout_layout = qtw.QHBoxLayout()
        hlaout_layout.addStretch(1)
        hlaout_layout.addWidget(self.connectdb_button)
        hlaout_layout.addStretch(1)

        # input /nested layout
        input1_label = qtw.QLabel("input 1 ")
        self.input_1 = qtw.QLineEdit()
        input1_hlayout = qtw.QHBoxLayout()
        input1_hlayout.addStretch(1)
        input1_hlayout.addWidget(input1_label)
        input1_hlayout.addWidget(self.input_1)
        input1_hlayout.addStretch(1)
        input1_hlayout.setAlignment(qtc.Qt.AlignHCenter)

        input2_label = qtw.QLabel("input 2 ")
        self.input_2 = qtw.QLineEdit()
        input2_hlayout = qtw.QHBoxLayout()
        input2_hlayout.addStretch(1)
        input2_hlayout.addWidget(input2_label)
        input2_hlayout.addWidget(self.input_2)
        input2_hlayout.addStretch(1)
        input2_hlayout.setAlignment(qtc.Qt.AlignHCenter)

        input3_label = qtw.QLabel("input 3 ")
        self.input_3 = qtw.QLineEdit()
        input3_hlayout = qtw.QHBoxLayout()
        input3_hlayout.addStretch(1)
        input3_hlayout.addWidget(input3_label)
        input3_hlayout.addWidget(self.input_3)
        input3_hlayout.addStretch(1)
        input3_hlayout.setAlignment(qtc.Qt.AlignHCenter)

        input4_label = qtw.QLabel("input 4 ")
        self.input_4 = qtw.QLineEdit()
        input4_hlayout = qtw.QHBoxLayout()
        input4_hlayout.addStretch(1)
        input4_hlayout.addWidget(input4_label)
        input4_hlayout.addWidget(self.input_4)
        input4_hlayout.addStretch(1)
        input4_hlayout.setAlignment(qtc.Qt.AlignHCenter)

        input5_label = qtw.QLabel("input 5 ")
        self.input_5 = qtw.QLineEdit()
        input5_hlayout = qtw.QHBoxLayout()
        input5_hlayout.addStretch(1)
        input5_hlayout.addWidget(input5_label)
        input5_hlayout.addWidget(self.input_5)
        input5_hlayout.addStretch(1)
        input5_hlayout.setAlignment(qtc.Qt.AlignHCenter)

        # select button
        self.select_button = qtw.QPushButton("start query ")
        select_buttonlayout = qtw.QHBoxLayout()
        select_buttonlayout.setAlignment(qtc.Qt.AlignHCenter)
        select_buttonlayout.addStretch(1)
        select_buttonlayout.addWidget(self.select_button)
        select_buttonlayout.addStretch(1)

        # hauptlayout
        haupt_layout = qtw.QFormLayout()

        haupt_layout.addRow(self.connectdb_button)
        haupt_layout.setVerticalSpacing(20)
        haupt_layout.addRow(input1_hlayout)
        haupt_layout.setVerticalSpacing(20)
        haupt_layout.addRow(input2_hlayout)
        haupt_layout.setVerticalSpacing(20)
        haupt_layout.addRow(input3_hlayout)
        haupt_layout.setVerticalSpacing(20)
        haupt_layout.addRow(input4_hlayout)
        haupt_layout.setVerticalSpacing(20)
        haupt_layout.addRow(input5_hlayout)
        haupt_layout.setVerticalSpacing(30)
        haupt_layout.addRow(select_buttonlayout)

        self.setLayout(haupt_layout)

        self.show()

        # Funktionalität
        self.connectdb_button.clicked.connect(self.connect_to_db)

        self.select_button.clicked.connect(self.query_data)

    def connect_to_db(self):
        self.database = qsql.QSqlDatabase.addDatabase('QSQLITE')
        self.database.setDatabaseName('qtdatabase.db')
        self.database.open()
        if self.database.isOpen():
            qtw.QMessageBox.about(self, 'connectet', "connection to db successful")

        # einfügen siehe pdf
        # if not self.db.open():
        #     error = self.db.lastError().text()
        # qtw.QMessageBox.critical(
        #     None, 'DB Connection Error',
        #     'Could not open database file: '
        #     f'{error}')
        # sys.exit(1)

    def query_data(self):
        mein_input = []

        item1 = self.input_1.text()
        item2 = self.input_2.text()
        item3 = self.input_3.text()
        item4 = self.input_4.text()
        item5 = self.input_5.text()

        mein_input.append(item1)
        mein_input.append(item2)
        mein_input.append(item3)
        mein_input.append(item4)
        mein_input.append(item5)

        self.query = qsql.QSqlQuery()
        self.query.prepare("INSERT INTO userinput(firstcolumns) VALUES(?)")

        self.query.addBindValue(mein_input)

        if not self.query.execBatch():
            print(self.query.lastError().text())

        self.close()
        # if not self.database.isOpen():
        #     qtw.QMessageBox.about(self, 'Erfolg', "Data inserted successfully")

if __name__ == '__main__':
    app = qtw.QApplication(sys.argv)
    w = Secondwindow()
    sys.exit(app.exec_())

我收到此错误

参数计数不匹配

当我插入列表而不是LineEdit输入时，该功能可以正常工作。

我检查了数据库中是否存在该表以及该列输出：['firstcolumns']

import sqlite3

# connect to database query starten
try:
    db_connection = sqlite3.connect("qtdatabase.db")

    cursor = db_connection.cursor()

    column_abfrage = '''SELECT * FROM userinput;'''

    cursor.execute(column_abfrage)
    cursor.close()

    names = list(map(lambda x: x[0], cursor.description))

    print(names)

except sqlite3.Error as error:
    print(error)

finally:
    if (db_connection):
        db_connection.close()
        print("db connection closed")

Answer 1

[sqlite是一个具有特定特征的数据库：如果您尝试打开该数据库时不存在该数据库，那么它将被创建，因此open()方法将始终返回True，因此会产生静默问题。

在这种情况下，建议始终使用完整路径，这可以明确地表示为：“ / full / path / of / database”或根据脚本的位置来构建，例如，如果数据库位于同一脚本中文件夹，则可以使用以下代码：

import os

# ...

current_dir = os.path.dirname(os.path.realpath(__file__))
db_path = os.path.join(current_dir, "qtdatabase.db")
self.database = qsql.QSqlDatabase.addDatabase('QSQLITE')
self.database.setDatabaseName(db_path)
if self.database.open():
    qtw.QMessageBox.about(self, 'connectet', "connection to db successful")

在您的情况下，您可能使用的某些IDE在运行脚本时使用的工作目录与脚本的位置不同。