如何在一个 QTableWidget 中显示 2 个具有一对多关系的 SQLite 表

Question

我在 Db 中有以下两个表，具有一对多关系：

self.c.execute("CREATE TABLE IF NOT EXISTS dispatch("
                       "id_dispatch INTEGER PRIMARY KEY AUTOINCREMENT,"
                       "d_date TEXT,"
                       "d_mill TEXT,"
                       "d_buyer TEXT,"
                       "d_addFreight INTEGER,"
                       "d_subFreight INTEGER,"
                       "d_amount INTEGER,"
                       "d_cd INTEGER,"
                       "d_comm INTEGER,"
                       "d_netAmount INTEGER)")
        self.c.execute("CREATE TABLE IF NOT EXISTS dispatch_products("
                       "dispatch_id INTEGER NOT NULL REFERENCES DISPATCH(id_dispatch),"
                       "product INTEGER,"
                       "quantity INTEGER,"
                       "rate INTEGER)")

我正在尝试将这两个表格合二为一并显示在一个表格中，使用以下代码：

def loadTable(self):
    connection = sqlite3.connect('main_databaseSample.db')
    query = "CREATE VIEW myview as SELECT d_buyer," \
            "d_date, product, quantity, rate, d_amount, d_addFreight, d_subFreight, d_netAmount from " \
            "dispatch, dispatch_products WHERE dispatch.id_dispatch = dispatch_products.dispatch_id"
    query = "SELECT * FROM myview"
    result = connection.execute(query)
    self.tableWidget.setRowCount(0)
    for row_number, row_data in enumerate(result):
        self.tableWidget.insertRow(row_number)
        for column_number, data in enumerate(row_data):
            self.tableWidget.setItem(row_number, column_number,QtWidgets.QTableWidgetItem(str(data)))
    connection.close()

问题：重复有多个产品的订单。如何消除具有一对多关系的多个条目？

样本数据：

dispatch table:
ID date   mill buyer addF subF amount cd comm netAmount
1  15-10  abc  A     0    0    100    0  0    100
2  16-10  xyz  B     0    0    200    0  0    200

dispatch_products table:
Dispatch_ID product qty rate
1           M       40  1
1           A       60  1
2           S       50  4

Code Output:
buyer date  product quantity rate amount addFreight subFreight NetAmount
A     15-10 M       40       1    100    0          0          100
A     15-10 A       60       1    100    0          0          100
B     16-10 S       50       4    200    0          0          200

Expected Output:
buyer date  product quantity rate amount addFreight subFreight NetAmount
A     15-10 M       40       1    100    0          0          100
            A       60       1                           
B     16-10 S       50       4    200    0          0          200

Answer 1

任务是检测是否存在相等的元素，我们必须向 View 添加一个元素，即 dispatch_id 或 id_dispatch 并对其进行排序。检测到 dispatch_id 的变化后，使用setSpan() 加入必要的行，如下所示：

from PyQt5 import QtCore, QtWidgets
import sqlite3

class Widget(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Widget, self).__init__(parent)
        button = QtWidgets.QPushButton("Press me")
        button.clicked.connect(self.load_table)
        self.tableWidget = QtWidgets.QTableWidget()

        lay = QtWidgets.QVBoxLayout(self)
        lay.addWidget(button)
        lay.addWidget(self.tableWidget)

    @QtCore.pyqtSlot()
    def load_table(self):
        self.tableWidget.setRowCount(0)
        self.tableWidget.setColumnCount(9)

        connection = sqlite3.connect('main_databaseSample.db')

        connection.execute("DROP VIEW IF EXISTS myview;")
        query = "CREATE VIEW myview as SELECT dispatch_id, d_buyer," \
            "d_date, product, quantity, rate, d_amount, d_addFreight, d_subFreight, d_netAmount from " \
            "dispatch, dispatch_products WHERE dispatch.id_dispatch = dispatch_products.dispatch_id " \
            "ORDER BY dispatch_id ASC;"
        connection.execute(query)
        query = "SELECT * FROM myview"
        result = connection.execute(query)
        last_id = -1
        start_row = 0
        for row, row_data in enumerate(result):
            self.tableWidget.insertRow(row)
            current_id, *other_values = row_data 
            for col, data in enumerate(other_values):
                it = QtWidgets.QTableWidgetItem(str(data))
                self.tableWidget.setItem(row, col, it)
            if last_id != current_id and last_id != -1:
                self.apply_span(start_row, row - start_row)
                start_row = row
            last_id = current_id
        if start_row != row:
            self.apply_span(start_row, self.tableWidget.rowCount() - start_row)

    def apply_span(self, row, nrow):
        if nrow <= 1:
            return
        for c in (0, 1, 5, 6, 7, 8):
            self.tableWidget.setSpan(row, c, nrow, 1)
            for r in range(row+1, row+nrow):
                t = self.tableWidget.takeItem(r, c)
                del t

if __name__ == '__main__':
    import sys
    app = QtWidgets.QApplication(sys.argv)
    w = Widget()
    w.show()
    sys.exit(app.exec_())

添加更多数据我们可以看到以下结果