Question

我正在使用PyQt和SQLAlchemy而SQLAlchemy不接受QStrings。有没有办法将QStrings传递给它，或者我必须每次都将QStrings转换为Python字符串？

谢谢。

以下是代码：

import sip
sip.setapi('QString', 2)

from sqlalchemy import create_engine
from sqlalchemy import Table, Column, Integer, String, Float, MetaData, ForeignKey
from sqlalchemy.sql import select, and_
from PyQt4 import QtGui, QtCore

class DbUtils(object):
    def __init__(self, db_file = None, parent = None):

        self.db = None
        self.db_connection = None
        self.db_file = str(db_file)

    def db_open(self):
        self.db = create_engine('sqlite:///' + self.db_file)
        self.db_connection = self.db.connect()

    def db_close(self):
        self.db_connection.close()

    def db_create_voltdrop(self):
        metadata = MetaData()

        tb_cable_brands = Table('cable_brands', metadata,
            Column('id', Integer, primary_key=True),
            Column('brand', String)
            )
        tb_cable_types = Table('cable_types', metadata,
            Column('id', Integer, primary_key=True),
            Column('brand_id', None, ForeignKey('cable_brands.id')),
            Column('type', String),
            Column('alpha', String)
            )
        tb_cable_data = Table('cable_data', metadata,
            Column('id', Integer, primary_key=True),
            Column('type_id', None, ForeignKey('cable_types.id')),
            Column('size', String),
            Column('resistance', Float)
            )
        metadata.create_all(self.db)

    def delete_cable_brand(self, cable_brand):
        cable_brand = str(cable_brand)
        metadata = MetaData()
        metadata.bind = self.db

        tb_cable_brands = Table('cable_brands', metadata, autoload = True)

        cable_brands = select([tb_cable_brands.c.brand],
                          and_(tb_cable_brands.c.brand == cable_brand)
                          )
        row = self.db_connection.execute(cable_brands)
        data = row.fetchone()
        if str(data[0]) == cable_brand:
            cable_brands = tb_cable_brands.delete().where(tb_cable_brands.c.brand == cable_brand)
            self.db_connection.execute(cable_brands)
            return True
        else:
            return False

Answer 1

您可以change the API to v2和PyQt始终使用常规Python字符串而不是QString。

修改

案例1 ：没有sip.setapi

import sys from PyQt4 import QtGui app = QtGui.QApplication(sys.argv) c = QtGui.QComboBox() c.addItems(["one","two"]) print c.currentText(), type(c.currentText()) c.show() sys.exit(app.exec_()) # Outputs one <class 'PyQt4.QtCore.QString'>

案例2 ：使用sip.setapi

import sip sip.setapi("QString",2) import sys from PyQt4 import QtGui app = QtGui.QApplication(sys.argv) c = QtGui.QComboBox() c.addItems(["one","two"]) print c.currentText(), type(c.currentText()) c.show() sys.exit(app.exec_()) # Outputs one <type 'unicode'>

PyQt - SQLAlchemy不接受QString

1 个答案: