python - 如何在数据库中使用 QSortFilterProxyModel？

Question

我有一个 QTableWidget，其中包含来自数据库的数据，我想实时搜索其内容(当我输入字母时，他会显示结果)？欢迎任何帮助。非常感谢。

这是我的代码:

class Filter:
    def __init__(self):
        object.__init__(self)
        self.db = QtSql.QSqlDatabase.addDatabase('QSQLITE')
        self.db.setDatabaseName("baza.db")
        self.filter_model= QSortFilterProxyModel()



    def sqlPodaci(self,okvir):
        okvir.setObjectName("Okvir aplikacije")
        okvir.resize(700,320)
        line_edit = QLineEdit(okvir)
        line_edit.setGeometry(20, 20, 205, 23)
        self.tableWidget = QtWidgets.QTableWidget(okvir)
        self.tableWidget.setGeometry(QtCore.QRect(20, 50, 620, 201))
        self.tableWidget.setAlternatingRowColors(True)
        self.tableWidget.setRowCount(3)
        self.tableWidget.horizontalHeader().setVisible(True)
        self.tableWidget.verticalHeader().setVisible(False)

        ###
        self.filter_model.setFilterKeyColumn(1)
        line_edit.textChanged.connect(self.filter_model.setFilterRegExp)
        ####
        self.Ucitavanje_podataka()

这是从数据库读取数据的代码:

def Ucitavanje_podataka(self):

status = self.db.open()
if status == False:
    QtWidgets.QMessageBox.warning(self, "Error", self.db.lastError().text(), QtWidgets.QMessageBox.Discard)
else:
    self.tableWidget.setColumnCount(6)
    self.tableWidget.setHorizontalHeaderLabels(['Id','Ime','Prezime','Godine','Adresa','Plata'])

    row = 0
    sql = " SELECT * FROM Zaposleni"
    query = QtSql.QSqlQuery(sql)
    while query.next():
        self.tableWidget.insertRow(row)
        ID=QtWidgets.QTableWidgetItem(str(query.value(0)))
        Ime = QtWidgets.QTableWidgetItem(str(query.value(1)))
        Prezime = QtWidgets.QTableWidgetItem(str(query.value(2)))
        Godine = QtWidgets.QTableWidgetItem(str(query.value(3)))
        Adresa = QtWidgets.QTableWidgetItem(str(query.value(4)))
        Plata = QtWidgets.QTableWidgetItem(str(query.value(5)))

        self.tableWidget.setItem(row,0,ID)
        self.tableWidget.setItem(row, 1, Ime)
        self.tableWidget.setItem(row, 2, Prezime)
        self.tableWidget.setItem(row, 3, Godine)
        self.tableWidget.setItem(row, 4, Adresa)
        self.tableWidget.setItem(row, 5, Plata)
        row=row+1

Answer 1

QTableWidget 有一个无法替换的预设模型，所以使用 QSortFilterProxyModel 是不可能的，所以你应该使用 QTableView，一个可能的解决方案对于过滤的主要问题是仅使用 QSqlQueryModel 并使用 LIKE 命令进行过滤。

from PyQt5 import QtWidgets, QtSql

def createConnection():
    db = QtSql.QSqlDatabase.addDatabase("QSQLITE")
    db.setDatabaseName("baza.db")
    if not db.open():
        QtWidgets.QMessageBox.critical(None, "Cannot open database",
                    "Unable to establish a database connection.\n"
                     "This example needs SQLite support. Please read "
                     "the Qt SQL driver documentation for information how "
                     "to build it.\n\n"
                     "Click Cancel to exit.", QtWidgets.QMessageBox.Cancel)
        return False
    return True

class Widget(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Widget, self).__init__(parent)
        lay = QtWidgets.QVBoxLayout(self)
        lineEdit = QtWidgets.QLineEdit()
        tableView = QtWidgets.QTableView()
        lay.addWidget(lineEdit)
        lay.addWidget(tableView)
        lineEdit.textChanged.connect(self.onTextChanged)

        self.model = QtSql.QSqlQueryModel()
        tableView.setModel(self.model)
        self.onTextChanged("")

    def onTextChanged(self, text):
        query = QtSql.QSqlQuery()
        query.prepare("SELECT * FROM Zaposleni WHERE Ime LIKE ?")
        query.addBindValue("{}%".format(text))
        query.exec_()
        self.model.setQuery(query)


if __name__ == '__main__':
    import sys

    app = QtWidgets.QApplication(sys.argv)
    if not createConnection():
        sys.exit(-1)
    w = Widget()
    w.show()
    sys.exit(app.exec_())

在前面的示例中，我们希望单词以 QLineEdit 的文本开头，如果您想查找它是否包含您必须将其替换为的单词:

query.addBindValue("%{}%".format(text))

---

如果你仍然想使用QSortFilterProxyModel，你可以看下面的例子:

from PyQt5 import QtCore, QtWidgets, QtSql

def createConnection():
    db = QtSql.QSqlDatabase.addDatabase("QSQLITE")
    db.setDatabaseName("baza.db")
    if not db.open():
        QtWidgets.QMessageBox.critical(None, "Cannot open database",
                    "Unable to establish a database connection.\n"
                     "This example needs SQLite support. Please read "
                     "the Qt SQL driver documentation for information how "
                     "to build it.\n\n"
                     "Click Cancel to exit.", QtWidgets.QMessageBox.Cancel)
        return False
    return True

class Widget(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Widget, self).__init__(parent)
        lay = QtWidgets.QVBoxLayout(self)
        lineEdit = QtWidgets.QLineEdit()
        tableView = QtWidgets.QTableView()
        lay.addWidget(lineEdit)
        lay.addWidget(tableView)
        lineEdit.textChanged.connect(self.onTextChanged)

        self.model = QtSql.QSqlQueryModel()
        self.model.setQuery("SELECT * FROM Zaposleni")

        self.proxy = QtCore.QSortFilterProxyModel()
        self.proxy.setSourceModel(self.model)
        self.proxy.setFilterKeyColumn(1)

        tableView.setModel(self.proxy)

    def onTextChanged(self, text):
        regex = "^{}".format(text)
        self.proxy.setFilterRegExp(QtCore.QRegExp(regex, QtCore.Qt.CaseInsensitive))


if __name__ == '__main__':
    import sys

    app = QtWidgets.QApplication(sys.argv)
    if not createConnection():
        sys.exit(-1)
    w = Widget()
    w.show()
    sys.exit(app.exec_())

在前面的示例中，我们希望单词以 QLineEdit 的文本开头，如果您想查找它是否包含您必须将其替换为的单词:

regex = "[{}]".format(text) if text else ""