Konstantin's questions

无法使用 QSqlTableModel 显示来自远程 QTableView 数据库的表（据我了解，与数据库本身的连接不起作用）。有一个代码不起作用，我无法弄清楚问题是什么......

import sys

from PySide2.QtCore import QSize
from PySide2.QtSql import QSqlDatabase, QSqlTableModel
from PySide2.QtWidgets import QApplication, QMainWindow, QTableView

db = QSqlDatabase.addDatabase("QMYSQL")
db.setHostName("server167.hosting.reg.ru")
db.setDatabaseName("db")
db.setUserName("<user name>")
db.setPassword("<password>")
db.open()

print(db, type(db))
if db.open():
    print("Database Open!")
else:
    print("Database NOT Open!")




class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()

        self.table = QTableView()

        self.model = QSqlTableModel(db=db)

        self.table.setModel(self.model)

        self.model.setTable("objects")
        self.model.select()

        self.setMinimumSize(QSize(1024, 600))
        self.setCentralWidget(self.table)


app = QApplication(sys.argv)
window = MainWindow()
window.show()
app.exec_()

我检查了100次连接数据，由于填充表的代码是100％执行的，我当然可以把连接器全部拿走，但我真的很想用Qt =）填充数据库表的代码：

import mysql.connector as mysql

mysql_conn = mysql.connect(
    host='server167.hosting.reg.ru',
    user='u1082920_root',
    password='1501kZn1501!',
    database = 'u1082920_docs_db'
)

with mysql_conn as connection:
    cursor = connection.cursor()
    cursor.execute("""DROP TABLE IF EXISTS objects""")
    cursor.execute("""CREATE TABLE objects(id INTEGER PRIMARY KEY, data TEXT NOT NULL,
                                            plan TEXT NOT NULL, name_plan TEXT NOT NULL)""")
    # # SQL запрос на вставку
    query = f"INSERT INTO objects (id, data,plan,name_plan) VALUES ('{1}', '{str(2)}', '{str(3)}', '{str(4)}')"
    cursor.execute(query)
    query = f"INSERT INTO objects (id, data,plan,name_plan) VALUES ('{2}', '{str(2)}', '{str(3)}', '{str(4)}')"
    cursor.execute(query)

    connection.commit()
    connection.close()

如何放置一组颜色QImage？

我这样做：

import sys
from PySide2.QtGui import QPixmap,  QImage
from PySide2.QtWidgets import QMainWindow, QApplication, QLabel, QHBoxLayout, QPushButton, QWidget
import numpy as np

# 1. Случайные числа в матрице N на M
N = 5
M = 5
data = np.random.random((N, M))
bins = np.array([0.00, 0.10, 0.15, 0.25, 0.30, 0.40, 0.6, 0.8, 0.95])
palette=np.array([[0, 30, 255], [0, 80, 255],[0, 100, 255],
                  [0, 255, 255], [20, 255, 255],[100, 100, 255],
                  [200, 50, 255], [255, 255, 100],[255, 255, 0]])


class MainWindow(QMainWindow):

    def __init__(self):
        super(MainWindow, self).__init__()
        self.title = "Image Viewer"
        self.setWindowTitle(self.title)
        central_widget = QWidget()
        box = QHBoxLayout()
        self.label = QLabel()
        self.button = QPushButton("Click me")
        self.button.clicked.connect(self.save_heat_map)
        box.addWidget(self.label)
        box.addWidget(self.button)
        central_widget.setLayout(box)
        self.setCentralWidget(central_widget)

    def save_heat_map(self):
        digitize = np.digitize(data, bins, right=True)
        digitize = np.expand_dims(digitize, axis=2)
        im = np.choose(digitize, palette, mode='clip')

        print(im)
        im = np.uint8(im)

        heat_map =  QPixmap(QImage(im, im.shape[1], im.shape[0], QImage.Format_RGB888))
        heat_map.save('test_output.png')


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

结果，我得到了一张图片，其中第一行颜色是正常的，而第二行和随后的颜色好像有偏移......我不知道为什么 =(

那些。第二行第一个像素的颜色应该(255, 255, 0)是(255, 0, 255)...

有一个大小为 500 x 200 的数据集（随机生成）：

N = 500
M = 200
data = numpy.random.random((N, M))

为了以颜色表示数据，我使用了我的 save_heat_map 函数，它创建了一个相称的白色 QPixmap（500 x 200），然后调用 create_heat_map 函数，它从数据中确定最大值并根据来自的值逐像素着色像素数据集，即 每个像素对应于某个数据值（像素 (0,0) 的颜色将取决于 data[0,0]）。然后保存结果的文件（大小为 500 x 200 的图片）。

问题：图片是500x200的时候很好，而不是5000x2000 =)如何让它更快？（颜色不重要）

import sys
from PySide2.QtGui import QPixmap, QColor
from PySide2.QtWidgets import QMainWindow, QApplication, QLabel, QHBoxLayout, QPushButton, QWidget
import numpy

# 1. Случайные числа в матрице N на M
N = 500
M = 200
data = numpy.random.random((N, M))


class MainWindow(QMainWindow):

    def __init__(self):
        super(MainWindow, self).__init__()
        self.title = "Image Viewer"
        self.setWindowTitle(self.title)
        central_widget = QWidget()
        box = QHBoxLayout()
        self.label = QLabel()
        self.button = QPushButton("Click me")
        self.button.clicked.connect(self.save_heat_map)
        box.addWidget(self.label)
        box.addWidget(self.button)
        central_widget.setLayout(box)
        self.setCentralWidget(central_widget)

    def save_heat_map(self):
        # создадим соразмерный pixmap_zone и сделаем его прозрачным
        pixmap_zone = QPixmap(N, M)
        pixmap_zone.fill(QColor(255, 255, 255, 255))
        # Нарисуем тепловую карту
        qimg_zone = pixmap_zone.toImage()
        heat_map = self.create_heat_map(data, N, M, qimg_zone)
        heat_map.save('test_output.png')


    def create_heat_map(self, arr, width: int, height: int, qimg_zone):
        max_el = arr.max()
        for x in range(width):
            for y in range(height):
                if arr[x, y] >= max_el:
                    qimg_zone.setPixelColor(x, y, QColor(255, 0, 0, 255))
                # красный
                elif max_el * 1.00 > arr[x, y] >= max_el * 0.90:
                    qimg_zone.setPixelColor(x, y, QColor(255, 10, 0, 255))
                # рыжий
                elif max_el * 0.90 > arr[x, y] >= max_el * 0.95:
                    qimg_zone.setPixelColor(x, y, QColor(255, 40, 0, 255))
                elif max_el * 0.95 > arr[x, y] >= max_el * 0.80:
                    qimg_zone.setPixelColor(x, y, QColor(255, 80, 0, 255))
                elif max_el * 0.80 > arr[x, y] >= max_el * 0.85:
                    qimg_zone.setPixelColor(x, y, QColor(255, 120, 0, 255))
                elif max_el * 0.85 > arr[x, y] >= max_el * 0.70:
                    qimg_zone.setPixelColor(x, y, QColor(255, 150, 0, 255))
                # желтый
                elif max_el * 0.70 > arr[x, y] >= max_el * 0.65:
                    qimg_zone.setPixelColor(x, y, QColor(255, 170, 0, 255))
                elif max_el * 0.65 > arr[x, y] >= max_el * 0.60:
                    qimg_zone.setPixelColor(x, y, QColor(255, 190, 0, 255))
                elif max_el * 0.60 > arr[x, y] >= max_el * 0.55:
                    qimg_zone.setPixelColor(x, y, QColor(255, 210, 0, 255))
                elif max_el * 0.55 > arr[x, y] >= max_el * 0.50:
                    qimg_zone.setPixelColor(x, y, QColor(255, 230, 0, 255))
                elif max_el * 0.50 > arr[x, y] >= max_el * 0.45:
                    qimg_zone.setPixelColor(x, y, QColor(255, 255, 0, 255))
                # салатовый
                elif max_el * 0.45 > arr[x, y] >= max_el * 0.475:
                    qimg_zone.setPixelColor(x, y, QColor(230, 255, 0, 255))
                elif max_el * 0.475 > arr[x, y] >= max_el * 0.450:
                    qimg_zone.setPixelColor(x, y, QColor(210, 255, 0, 255))
                elif max_el * 0.450 > arr[x, y] >= max_el * 0.425:
                    qimg_zone.setPixelColor(x, y, QColor(180, 255, 0, 255))
                elif max_el * 0.425 > arr[x, y] >= max_el * 0.400:
                    qimg_zone.setPixelColor(x, y, QColor(150, 255, 0, 255))
                # зеленый
                elif max_el * 0.400 > arr[x, y] >= max_el * 0.39:
                    qimg_zone.setPixelColor(x, y, QColor(100, 255, 0, 255))
                elif max_el * 0.39 > arr[x, y] >= max_el * 0.38:
                    qimg_zone.setPixelColor(x, y, QColor(70, 255, 0, 255))
                elif max_el * 0.38 > arr[x, y] >= max_el * 0.37:
                    qimg_zone.setPixelColor(x, y, QColor(40, 255, 0, 255))
                elif max_el * 0.37 > arr[x, y] >= max_el * 0.36:
                    qimg_zone.setPixelColor(x, y, QColor(10, 255, 0, 255))
                elif max_el * 0.36 > arr[x, y] >= max_el * 0.35:
                    qimg_zone.setPixelColor(x, y, QColor(0, 255, 0, 255))

                # голубой
                elif max_el * 0.35 > arr[x, y] >= max_el * 0.245:
                    qimg_zone.setPixelColor(x, y, QColor(0, 255, 40, 255))
                elif max_el * 0.245 > arr[x, y] >= max_el * 0.240:
                    qimg_zone.setPixelColor(x, y, QColor(0, 255, 80, 255))
                elif max_el * 0.240 > arr[x, y] >= max_el * 0.235:
                    qimg_zone.setPixelColor(x, y, QColor(0, 255, 100, 255))
                elif max_el * 0.235 > arr[x, y] >= max_el * 0.23:
                    qimg_zone.setPixelColor(x, y, QColor(0, 255, 120, 255))
                elif max_el * 0.23 > arr[x, y] >= max_el * 0.225:
                    qimg_zone.setPixelColor(x, y, QColor(0, 255, 150, 255))
                elif max_el * 0.225 > arr[x, y] >= max_el * 0.22:
                    qimg_zone.setPixelColor(x, y, QColor(0, 255, 210, 255))
                elif max_el * 0.22 > arr[x, y] >= max_el * 0.215:
                    qimg_zone.setPixelColor(x, y, QColor(0, 255, 240, 255))
                elif max_el * 0.215 > arr[x, y] >= max_el * 0.21:
                    qimg_zone.setPixelColor(x, y, QColor(0, 255, 255, 255))

                # темно-голубой
                elif max_el * 0.21 > arr[x, y] >= max_el * 0.19:
                    qimg_zone.setPixelColor(x, y, QColor(0, 220, 255, 255))
                elif max_el * 0.19 > arr[x, y] >= max_el * 0.18:
                    qimg_zone.setPixelColor(x, y, QColor(0, 210, 255, 255))
                elif max_el * 0.18 > arr[x, y] >= max_el * 0.17:
                    qimg_zone.setPixelColor(x, y, QColor(0, 200, 255, 255))
                elif max_el * 0.17 > arr[x, y] >= max_el * 0.16:
                    qimg_zone.setPixelColor(x, y, QColor(0, 190, 255, 255))
                elif max_el * 0.16 > arr[x, y] >= max_el * 0.15:
                    qimg_zone.setPixelColor(x, y, QColor(0, 160, 255, 255))
                elif max_el * 0.15 > arr[x, y] >= max_el * 0.14:
                    qimg_zone.setPixelColor(x, y, QColor(0, 150, 255, 255))
                #     синий
                elif max_el * 0.14 > arr[x, y] >= max_el * 0.13:
                    qimg_zone.setPixelColor(x, y, QColor(0, 130, 255, 255))
                elif max_el * 0.13 > arr[x, y] >= max_el * 0.125:
                    qimg_zone.setPixelColor(x, y, QColor(0, 110, 255, 255))
                elif max_el * 0.125 > arr[x, y] >= max_el * 0.115:
                    qimg_zone.setPixelColor(x, y, QColor(0, 90, 255, 255))
                elif max_el * 0.115 > arr[x, y] >= max_el * 0.11:
                    qimg_zone.setPixelColor(x, y, QColor(0, 70, 255, 255))
                elif max_el * 0.11 > arr[x, y] >= max_el * 0.108:
                    qimg_zone.setPixelColor(x, y, QColor(0, 50, 255, 255))
                elif max_el * 0.108 > arr[x, y] >= max_el * 0.107:
                    qimg_zone.setPixelColor(x, y, QColor(0, 40, 255, 255))
                elif max_el * 0.107 > arr[x, y] >= max_el * 0.106:
                    qimg_zone.setPixelColor(x, y, QColor(0, 30, 255, 255))
                elif max_el * 0.106 > arr[x, y] >= max_el * 0.102:
                    qimg_zone.setPixelColor(x, y, QColor(0, 20, 255, 255))
                elif max_el * 0.102 > arr[x, y] >= max_el * 0.101:
                    qimg_zone.setPixelColor(x, y, QColor(0, 0, 255, 255))
        return qimg_zone


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

有一个很长的清单。如何保证将其发送到服务器并取回？我已经尝试过对数据进行切片）对于客户端，使用变量 var = 8000，不会完整返回列表...

服务器代码：

import socketserver

class ThredingTCPServer(socketserver.ThreadingMixIn, socketserver.TCPServer):
    pass

class EchoTCPHandler(socketserver.BaseRequestHandler):

    def handle(self):
        def recvall(request):
            BUFF_SIZE = 4096  # 4 KiB
            data = b''
            while True:
                part = request.recv(BUFF_SIZE)
                data += part
                if len(part) < BUFF_SIZE:
                    break
            return data

        full_data = recvall(self.request)
        print(f'Adress: {self.client_address[0]}')
        print(f'Data: {len(full_data)} {full_data}')
        # некая операция
        #d = eval(full_data)
        #d = d[::-1]

        msg = str(full_data).encode()
        self.request.sendall(msg)

if __name__ == '__main__':
    with ThredingTCPServer(('', 8888), EchoTCPHandler) as server:
        server.serve_forever()

客户端代码：

import socket


def recvall(sock):
    BUFF_SIZE = 4096 # 4 KiB
    data = b''
    while True:
        part = sock.recv(BUFF_SIZE)
        data += part
        if len(part) < BUFF_SIZE:
            break
    return data


var = 8000
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect(('127.0.0.1', 8888))
msg = str([i*i for i in range(var)]).encode()
sock.send(msg)
res = recvall(sock)
ans = res.decode()
print(len(ans), ans)
sock.close()

excel（data25.xls）中有数据，我正在尝试基于它们构建图表。事实证明不是很好......即。由于最大值是2969，而且下降的很快，所以整个颜色网格都在最大值附近（saved_figure.png），基本上整个图都是蓝色的，不好...

我这样构建图表：

import xlwings as xw
import matplotlib.pyplot as plt
 
def get_row_col_index(sheet):
    'Индексы для диапазона что бы забрать данные'
    row = 0
    col = 0
    # find col
    for i in range(1, 5000):
        val = sheet.range((1, i)).value
        if val == None:
            col = (1, i - 1)
            break
    # find row
    for i in range(1, 5000):
        val = sheet.range((i, 1)).value
        if val == None:
            row = (i - 1, 1)
            break
 
    return row, col
 
def get_data_in_excel(row: tuple, col: tuple) -> list:
    val = sheet.range((2, 2), (row[0], col[1])).options(
        ndim=2).value  # с 2 - т.к. нужно ислючить размерность длины по X, Y
    return val
 
wb = xw.Book(f'data25.xls')
sheet = wb.sheets['Лист1']
 
row, col = get_row_col_index(sheet)
val = get_data_in_excel(row, col)
 
plt.imshow(val, cmap='jet', interpolation = 'bicubic', vmax=0.5)
plt.show()
# plt.savefig('saved_figure.png')

我得到：

我想得到这样的东西：

数据：excel链接

PS。所需的图表是从基于相同 excel 数据的另一个程序中获得的。

有这样的数据：

从他们那里，我可以提取联系人姓名（或者更确切地说，甚至是单独的名字和姓氏）：

SELECT
    C.contactname,
    SUBSTRING(C.contactname, 1, CHARINDEX(', ', C.contactname) - 1) AS Lastname,
    SUBSTRING(C.contactname,
                 CHARINDEX(' ', C.contactname) + 1,
                 LEN(C.contactname) - CHARINDEX(' ', C.contactname)) AS Firstname
FROM [Sales].[Customers] AS C

现在如何在这里应用一个条件来排除那些以“M”开头的名字（名字）？（如迈克尔等）

是否可以绘制一个不单调但带有渐变的 QPolygon。我的代码：

from PyQt5.QtWidgets import QApplication, QMainWindow
import sys
from PyQt5.QtGui import QPen,QPainter, QPolygon, QRadialGradient, QBrush, QColor
from PyQt5.QtCore import QPoint, Qt


class Window(QMainWindow):
    def __init__(self):
        super().__init__()
        self.title = "PyQt5 Drawing Polygon"
        self.width = 900
        self.height = 900
        self.InitWindow()

    def InitWindow(self):
        self.setWindowTitle(self.title)
        self.setGeometry(0,0, self.width, self.height)
        self.show()

    def paintEvent(self, event):
        painter = QPainter(self)
        gradient = QRadialGradient(50, 50, 50, 50, 50)
        gradient.setColorAt(0, QColor.fromRgbF(100, 125, 0, 0.5))
        gradient.setColorAt(1, QColor.fromRgbF(0, 255, 0, 0.5))
        brush = QBrush(gradient)
        pen = QPen(brush, 50, Qt.SolidLine)
        pen.setJoinStyle(Qt.RoundJoin)
        pen.setCapStyle(Qt.RoundCap)
        painter.setPen(pen)

        points = QPolygon([
            QPoint(80,80),
            QPoint(80,500),
            QPoint(500,80),
            QPoint(500,500)
        ])

        painter.drawPolyline(points)

App = QApplication(sys.argv)
window = Window()
sys.exit(App.exec())

所需结果的示例（如果可能的话......）：

有一张宽大的桌子。如何使滚动的第一列始终可见？

import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtCore import Qt


class MainWindow(QtWidgets.QMainWindow):
    def __init__(self):
        super().__init__()

        self.table_data = QtWidgets.QTableWidget(1, 20, self)
        self.setCentralWidget(self.table_data)


app = QtWidgets.QApplication(sys.argv)
window = MainWindow()
window.show()
app.exec_()

有这样一张图：

import matplotlib.pyplot as plt
 
y=[5, 5, 4, 4, 3, 3]
x=[0, 1, 1, 2, 2, 3]
 
plt.plot(x, y)
plt.show()

如何让它不是用一条线构建，而是用中断来构建，可以这么说（我不知道它是如何正确调用的，所以我用油漆画了它）？

如何为闪存驱动器上的 bat 文件创建快捷方式？我在 python 文件夹中的闪存驱动器上安装了嵌入式 python，将我的 gui.py 脚本（PyQt5 上的 GUI）放在那里并创建了一个 .bat 文件来运行它：

@echo off
%CD%\python.exe gui.pyw %*
@pause

如何制作一个可以启动.bat的快捷方式？

数据库以BLOB.

选择单元格并按下“下载文件...”按钮时，如何从数据库中卸载此文件？（代码旁边应该是test_BLOB.pdf）

最小的例子：

import sys
import os
from PySide2 import QtSql
from PySide2 import QtWidgets
from PySide2 import QtCore


class Storage_app(QtWidgets.QMainWindow):

    def __init__(self, parent=None) -> None:
        super().__init__()
        self.createConnection()
        self.fillTable()  # !!! тестовое заполнение базы данных
        self.createModel()
        self.initUI()

        self.centralWidget = QtWidgets.QWidget()
        self.setCentralWidget(self.centralWidget)
        btn_save = QtWidgets.QPushButton("Скачать файл из БД")
        btn_save.clicked.connect(self.save_file)
        layout = QtWidgets.QVBoxLayout(self.centralWidget)
        layout.addWidget(self.view)
        layout.addWidget(btn_save)

        if not parent:
            self.show()

    def save_file(self):
        print("Как сохранить этот файл из базы данных? =(")

    def createConnection(self):
        self.db = QtSql.QSqlDatabase.addDatabase("QSQLITE")
        self.db.setDatabaseName("local_base.db")  # !!! .db
        if not self.db.open():
            print("Cannot establish a database connection")
            return False

    def fillTable(self):
        """
        Вспомогательная функция заполнениия базы данных
        Отключить после тестового запуска
        """
        file_path = (f"{os.getcwd()}\\test_BLOB.pdf")
        test_BLOB = self.convertToBinaryData(file_path)
        test_BLOB = QtCore.QByteArray(test_BLOB)

        self.db.transaction()
        q = QtSql.QSqlQuery()
        #
        q.exec_("DROP TABLE IF EXISTS company;")
        q.exec_("CREATE TABLE company ("
                "id INT PRIMARY KEY, "
                "name_company TEXT NOT NULL, "
                "blob_data BLOB NOT NULL );")

        # Вставка тестовых значений
        query = QtSql.QSqlQuery()
        query.prepare("INSERT INTO company (id, name_company, blob_data) "
                      "VALUES (:id, :name_company, :blob_data)")

        query.bindValue(":id", 1)
        query.bindValue(":name_company", 'АО КОПЫТА')
        query.bindValue(":blob_data", test_BLOB)
        query.exec_()

        query = QtSql.QSqlQuery()
        query.prepare("INSERT INTO company (id, name_company, blob_data) "
                      "VALUES (:id, :name_company, :blob_data)")

        query.bindValue(":id", 2)
        query.bindValue(":name_company", 'АО РОГА')
        query.bindValue(":blob_data", test_BLOB)
        query.exec_()

        self.db.commit()

    def createModel(self):
        """
        Создание модели для отображения
        """
        self.model = QtSql.QSqlRelationalTableModel()
        self.model.setTable("company")
        self.model.setHeaderData(0, QtCore.Qt.Horizontal, "id")
        self.model.setHeaderData(1, QtCore.Qt.Horizontal, "Наиманование")
        self.model.setHeaderData(2, QtCore.Qt.Horizontal, "Документы")
        self.model.select()

    def initUI(self):
        self.view = QtWidgets.QTableView()
        self.view.setModel(self.model)
        mode = QtWidgets.QAbstractItemView.SingleSelection
        self.view.setSelectionMode(mode)


    def closeEvent(self, event):
        if (self.db.open()):
            self.db.close()

    def convertToBinaryData(self, file_path):
        # Конвертирование в BLOB
        with open(file_path, 'rb') as file:
            blobData = file.read()
        return blobData


if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    app.setStyle('Fusion')
    w = Storage_app()
    app.exec_()

如何QSqlRelationalTableModel防止编辑表格的列？例如，有两个表格category，equipment如何禁用id表格category和Category表格中列的编辑equipment？

最小的例子：

import sys
from PyQt5 import QtSql
from PyQt5.Qt import *

class Example(QMainWindow):
    def __init__(self):
        super().__init__()

        self.createConnection()
        self.fillTable()  # !!!
        self.createModel()
        self.initUI()

        self.centralWidget = QWidget()
        self.setCentralWidget(self.centralWidget)
        self.table_box = QComboBox()
        self.table_box.addItems(["Оборудование", "Категории"])
        self.table_box.activated[str].connect(self.table_select)


        layout = QVBoxLayout(self.centralWidget)
        layout.addWidget(self.view)
        layout.addWidget(self.table_box)

    def createConnection(self):
        self.db = QtSql.QSqlDatabase.addDatabase("QSQLITE")
        self.db.setDatabaseName("test_1318914.db")  # !!! .db
        if not self.db.open():
            print("Cannot establish a database connection")
            return False

    def fillTable(self):
        self.db.transaction()
        q = QtSql.QSqlQuery()
        #                             vvvvvvvv
        q.exec_("DROP TABLE IF EXISTS category;")
        q.exec_("CREATE TABLE category (id INT PRIMARY KEY, catname TEXT);")
        q.exec_("INSERT INTO category VALUES (1, 'Расходники');")
        q.exec_("INSERT INTO category VALUES (2, 'Носители');")

        #                             vvvv
        q.exec_("DROP TABLE IF EXISTS equipment;")
        q.exec_("CREATE TABLE equipment (Name TEXT, Quantity INT, Category INT);")
        q.exec_("INSERT INTO equipment VALUES ('Барабан для принтера', 8, 1);")
        q.exec_("INSERT INTO equipment VALUES ('Бумага для принтера', 3, 1);")
        q.exec_("INSERT INTO equipment VALUES ('Дискета', 10, 2);")
        self.db.commit()

    def createModel(self):
        self.model = QtSql.QSqlRelationalTableModel()
        self.model.setTable("equipment")
        self.model.select()

    def initUI(self):
        self.view = QTableView()
        self.view.setModel(self.model)
        self.view.setColumnWidth(0, 150)
        mode = QAbstractItemView.SingleSelection
        self.view.setSelectionMode(mode)

    def table_select(self, text):
        if text == 'Категории':
            self.model.setTable("category")
            self.model.select()
        elif text == 'Оборудование':
            self.model.setTable("equipment")
            self.model.select()

    def closeEvent(self, event):
        if (self.db.open()):
            self.db.close()



if __name__ == '__main__':
    app = QApplication(sys.argv)
    w = Example()
    w.setWindowTitle("No edit")
    w.resize(430, 250)
    w.show()

我意识到我需要创建自己的继承类QSqlRelationalTableModel并覆盖该方法flags......我试图重做 Qt 示例，但它不起作用 =( 所有表都变得不可编辑。

有две桌子category和equipment。
我正在尝试为他们制作一个过滤器，但事实证明equipment它可以在其中工作，
但category不能在...... =（

最小的例子：

import re
import sys
from PyQt5 import QtSql
from PyQt5.Qt import *

class Example(QMainWindow):
    def __init__(self):
        super().__init__()

        self.createConnection()
        self.fillTable()  # !!!
        self.createModel()
        self.initUI()

        self.centralWidget = QWidget()
        self.setCentralWidget(self.centralWidget)
        self.table_box = QComboBox()
        self.table_box.addItems(["Оборудование", "Категории"])
        self.table_box.activated[str].connect(self.table_select)
        search_str = QLineEdit()
        search_str.setPlaceholderText("Введите строку поиска")
        search_str.textChanged.connect(self.update_filter)

        layout = QVBoxLayout(self.centralWidget)
        layout.addWidget(self.view)
        layout.addWidget(self.table_box)
        layout.addWidget(search_str)

    def createConnection(self):
        self.db = QtSql.QSqlDatabase.addDatabase("QSQLITE")
        self.db.setDatabaseName("test_1318914.db")  # !!! .db
        if not self.db.open():
            print("Cannot establish a database connection")
            return False

    def fillTable(self):
        self.db.transaction()
        q = QtSql.QSqlQuery()
        #                             vvvvvvvv
        q.exec_("DROP TABLE IF EXISTS category;")
        q.exec_("CREATE TABLE category (id INT PRIMARY KEY, catname TEXT);")
        q.exec_("INSERT INTO category VALUES (1, 'Расходники');")
        q.exec_("INSERT INTO category VALUES (2, 'Носители');")

        #                             vvvv
        q.exec_("DROP TABLE IF EXISTS equipment;")
        q.exec_("CREATE TABLE equipment (Name TEXT, Quantity INT, Category INT);")
        q.exec_("INSERT INTO equipment VALUES ('Барабан для принтера', 8, 1);")
        q.exec_("INSERT INTO equipment VALUES ('Бумага для принтера', 3, 1);")
        q.exec_("INSERT INTO equipment VALUES ('Дискета', 10, 2);")
        self.db.commit()

    def createModel(self):
        self.model = QtSql.QSqlRelationalTableModel()
        self.model.setTable("equipment")
        self.model.select()

    def initUI(self):
        self.view = QTableView()
        self.view.setModel(self.model)
        self.view.setColumnWidth(0, 150)
        mode = QAbstractItemView.SingleSelection
        self.view.setSelectionMode(mode)


    def update_filter(self, text):
        if self.table_box.currentText() == 'Категории':
            s = re.sub("[\W_]+", "", text)
            filter_str = 'FROM category WHERE catname LIKE "%{}%"'.format(s)
            self.model.setFilter(filter_str)
        elif self.table_box.currentText() == 'Оборудование':
            s = re.sub("[\W_]+", "", text)
            filter_str = 'Name LIKE "%{}%"'.format(s)
            self.model.setFilter(filter_str)

    def table_select(self, text):
        if text == 'Категории':
            self.model.setTable("category")
            self.model.select()
        elif text == 'Оборудование':
            self.model.setTable("equipment")
            self.model.select()

    def closeEvent(self, event):
        if (self.db.open()):
            self.db.close()



if __name__ == '__main__':
    app = QApplication(sys.argv)
    w = Example()
    w.setWindowTitle("Search")
    w.resize(430, 250)
    w.show()
    sys.exit(app.exec_())

Действия:

1. 我运行示例，出现一个视图窗口：

2. 我输入QLineEdit例如“Ba”，他选择了正确的：

3. 切换到“类别”：

4. 当您尝试在“类别”表中搜索时，它不会搜索 =(

共有三张表：company（公司）、department（部门）、subdivision（细分）。请帮我写一个这样的查询：删除id = 2的公司“Hooves”，因为没有这样的公司，然后分别删除id_company = 2的部门，对于每个要删除的部门，删除所有子部门。

例如，我想出了如何从链接表中删除DELETE FROM Department WHERE id_company = 2，但是如何删除要删除的部门的细分（细分）？

BEGIN TRANSACTION;
CREATE TABLE IF NOT EXISTS "Company" (
    "id"    INTEGER,
    "name_company"  TEXT
);
CREATE TABLE IF NOT EXISTS "Department" (
    "id"    INTEGER,
    "id_company"    INTEGER,
    "name department"   TEXT
);
CREATE TABLE IF NOT EXISTS "Subdivision" (
    "id"    INTEGER,
    "id_department" INTEGER,
    "name_sub"  TEXT
);
INSERT INTO "Company" VALUES (1,'Рога');
INSERT INTO "Company" VALUES (2,'Копыта');
INSERT INTO "Company" VALUES (3,'Енот');
INSERT INTO "Department" VALUES (1,2,'Отдел копыт');
INSERT INTO "Department" VALUES (2,1,'Отдел рогов');
INSERT INTO "Department" VALUES (3,3,'Енотный отдел');
INSERT INTO "Subdivision" VALUES (1,1,'Рога и нетолько');
COMMIT;

我有一个包含两个表good和category.
通过QSqlRelationalTableModel表格的可视化，用值good替换列来实现。Сategorycatnameid

按下按钮时btnAdd = QPushButton("&Добавить запись")，在数据库中实现了一条记录在一个表中good，填写时需要指明该记录属于哪个记录（以后会正常工作）。id categoryQSqlRelationalTableModel

如何代替self.line_edit_category QCombobox表格中的数据，category以便清楚用户输入的内容。

比如一个下拉列表，让用户不能输入错误的东西：

import sys
from PyQt5 import QtSql
from PyQt5.Qt import *


class Dialog(QDialog):
    def __init__(self):
        super().__init__()
        self.setWindowTitle('Input Dialog')
        self.line_edit_name = QLineEdit()
        self.line_edit_quantity = QLineEdit()
        self.line_edit_category = QLineEdit()

        form_layout = QFormLayout()
        form_layout.addRow('Name:', self.line_edit_name)
        form_layout.addRow('quantity:', self.line_edit_quantity)
        form_layout.addRow('category:', self.line_edit_category)

        button_box = QDialogButtonBox(
            QDialogButtonBox.Ok | QDialogButtonBox.Cancel)
        button_box.accepted.connect(self.accept)
        button_box.rejected.connect(self.reject)

        main_layout = QVBoxLayout(self)
        main_layout.addLayout(form_layout)
        main_layout.addWidget(button_box)


class Example(QMainWindow):
    def __init__(self):
        super().__init__()

        self.createConnection()
        self.fillTable()  # !!!
        self.createModel()
        self.initUI()

        self.centralWidget = QWidget()
        self.setCentralWidget(self.centralWidget)
        btnAdd = QPushButton("&Добавить запись")
        btnAdd.clicked.connect(self.addRecord)
        btnDel = QPushButton("&Удалить запись")
        btnDel.clicked.connect(self.delRecord)

        layout = QVBoxLayout(self.centralWidget)
        layout.addWidget(self.view)
        layout.addWidget(btnAdd)
        layout.addWidget(btnDel)

    def createConnection(self):
        self.db = QtSql.QSqlDatabase.addDatabase("QSQLITE")
        self.db.setDatabaseName("test_1318914.db")  # !!! .db
        if not self.db.open():
            print("Cannot establish a database connection")
            return False

    def fillTable(self):
        self.db.transaction()
        q = QtSql.QSqlQuery()
        #                             vvvvvvvv
        q.exec_("DROP TABLE IF EXISTS category;")
        q.exec_("CREATE TABLE category (id INT PRIMARY KEY, catname TEXT);")
        q.exec_("INSERT INTO category VALUES (1, 'Расходники');")
        q.exec_("INSERT INTO category VALUES (2, 'Носители');")

        #                             vvvv
        q.exec_("DROP TABLE IF EXISTS good;")
        q.exec_("CREATE TABLE good (Name TEXT, Quantity INT, Category INT);")
        q.exec_("INSERT INTO good VALUES ('Барабан для принтера', 8, 1);")
        q.exec_("INSERT INTO good VALUES ('Бумага для принтера', 3, 1);")
        q.exec_("INSERT INTO good VALUES ('Дискета', 10, 2);")
        self.db.commit()

    def createModel(self):
        self.model = QtSql.QSqlRelationalTableModel()
        self.model.setTable("good")
        self.model.setHeaderData(0, Qt.Horizontal, "Название")
        self.model.setHeaderData(1, Qt.Horizontal, "Кол-во")
        self.model.setHeaderData(2, Qt.Horizontal, "Категория")
        self.set_relation()
        self.model.select()

    def initUI(self):
        self.view = QTableView()
        self.view.setModel(self.model)
        self.view.setColumnWidth(0, 150)
        mode = QAbstractItemView.SingleSelection
        self.view.setSelectionMode(mode)

    def closeEvent(self, event):
        if (self.db.open()):
            self.db.close()

    def set_relation(self):
        self.model.setRelation(2, QtSql.QSqlRelation(
            "category",
            "id",
            "catname"
        ))

    def addRecord(self):
        inputDialog = Dialog()
        rez = inputDialog.exec()
        if not rez:
            msg = QMessageBox.information(self, 'Внимание', 'Диалог сброшен.')
            return

        name = inputDialog.line_edit_name.text()
        quantity = inputDialog.line_edit_quantity.text()
        category = inputDialog.line_edit_category.text()
        if (not name) or (not quantity) or (not category):
            msg = QMessageBox.information(self,
                                          'Внимание', 'Заполните пожалуйста все поля.')
            return

        r = self.model.record()
        r.setValue(0, name)
        r.setValue(1, int(quantity))
        r.setValue(2, int(category))

        self.model.insertRecord(-1, r)
        self.model.select()

    def delRecord(self):
        row = self.view.currentIndex().row()
        if row == -1:
            msg = QMessageBox.information(self,
                                          'Внимание', 'Выберите запись для удаления.')
            return

        name = self.model.record(row).value(0)
        quantity = self.model.record(row).value(1)
        category = self.model.record(row).value(2)

        inputDialog = Dialog()
        inputDialog.setWindowTitle('Удалить запись ???')
        inputDialog.line_edit_name.setText(name)
        inputDialog.line_edit_quantity.setText(str(quantity))
        inputDialog.line_edit_category.setText(str(category))
        rez = inputDialog.exec()
        if not rez:
            msg = QMessageBox.information(self, 'Внимание', 'Диалог сброшен.')
            return

        self.model.setRelation(2, QtSql.QSqlRelation())
        self.model.select()
        self.model.removeRow(row)
        self.set_relation()
        self.model.select()

        msg = QMessageBox.information(self, 'Успех', 'Запись удалена.')


if __name__ == '__main__':
    app = QApplication(sys.argv)
    w = Example()
    w.setWindowTitle("QRelationalSqlTableModel")
    w.resize(430, 250)
    w.show()
    sys.exit(app.exec_())

通常我一直使用示例来识别发件人按钮：

import sys
from PySide2.QtWidgets import QMainWindow, QPushButton, QApplication

class Example(QMainWindow):

    def __init__(self):
        super().__init__()

        self.initUI()


    def initUI(self):

        btn1 = QPushButton("Button 1", self)
        btn1.move(30, 50)

        btn2 = QPushButton("Button 2", self)
        btn2.move(150, 50)

        btn1.clicked.connect(self.buttonClicked)
        btn2.clicked.connect(self.buttonClicked)

        self.statusBar()

        self.setGeometry(300, 300, 290, 150)
        self.setWindowTitle('Event sender')
        self.show()


    def buttonClicked(self):

        sender = self.sender()
        print(sender)
        self.statusBar().showMessage(sender.text() + ' was pressed')


if __name__ == '__main__':

    app = QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())

但是我有这样一个问题，如果
btn1 = QPushButton("", self)和btn1 = QPushButton("", self)，
如何理解按下了哪个按钮？

有一个表格，其中除了通常的信息外，还以表格形式存储了PDF文档，BLOB以问号的形式显示如下：

如何让这些“问号”更人性化？（我想在那里放一些图标或其他东西，否则我立即期待用户的问题：“这些问号是什么？”）

最小示例（在代码文件旁边，您需要放置任何名为test_BLOB.jpg的文件，以便可以转换为BLOB）：

import sys
import os
from PySide2 import QtSql
from PySide2 import QtWidgets
from PySide2 import QtCore


class Storage_app(QtWidgets.QMainWindow):

    def __init__(self, parent=None) -> None:
        super().__init__()
        self.createConnection()
        self.fillTable()  # !!! тестовое заполнение базы данных
        self.createModel()
        self.initUI()

        self.centralWidget = QtWidgets.QWidget()
        self.setCentralWidget(self.centralWidget)
        layout = QtWidgets.QVBoxLayout(self.centralWidget)
        layout.addWidget(self.view)

        if not parent:
            self.show()

    def createConnection(self):
        self.db = QtSql.QSqlDatabase.addDatabase("QSQLITE")
        self.db.setDatabaseName("local_base.db")  # !!! .db
        if not self.db.open():
            print("Cannot establish a database connection")
            return False

    def fillTable(self):
        """
        Вспомогательная функция заполнениия базы данных
        Отключить после тестового запуска
        """
        file_path = (f"{os.getcwd()}\\test_BLOB.jpg")
        test_BLOB = self.convertToBinaryData(file_path)
        test_BLOB = QtCore.QByteArray(test_BLOB)

        self.db.transaction()
        q = QtSql.QSqlQuery()
        #
        q.exec_("DROP TABLE IF EXISTS company;")
        q.exec_("CREATE TABLE company ("
                "id INT PRIMARY KEY, "
                "name_company TEXT NOT NULL, "
                "blob_data BLOB NOT NULL );")

        # Вставка тестовых значений
        query = QtSql.QSqlQuery()
        query.prepare("INSERT INTO company (id, name_company, blob_data) "
                      "VALUES (:id, :name_company, :blob_data)")

        query.bindValue(":id", 1)
        query.bindValue(":name_company", 'АО КОПЫТА')
        query.bindValue(":blob_data", test_BLOB)
        query.exec_()

        query = QtSql.QSqlQuery()
        query.prepare("INSERT INTO company (id, name_company, blob_data) "
                      "VALUES (:id, :name_company, :blob_data)")

        query.bindValue(":id", 2)
        query.bindValue(":name_company", 'АО РОГА')
        query.bindValue(":blob_data", test_BLOB)
        query.exec_()

        self.db.commit()

    def createModel(self):
        """
        Создание модели для отображения
        """
        self.model = QtSql.QSqlRelationalTableModel()
        self.model.setTable("company")
        self.model.setHeaderData(0, QtCore.Qt.Horizontal, "id")
        self.model.setHeaderData(1, QtCore.Qt.Horizontal, "Наиманование")
        self.model.setHeaderData(2, QtCore.Qt.Horizontal, "Документы")
        self.model.select()

    def initUI(self):
        self.view = QtWidgets.QTableView()
        self.view.setModel(self.model)
        mode = QtWidgets.QAbstractItemView.SingleSelection
        self.view.setSelectionMode(mode)


    def closeEvent(self, event):
        if (self.db.open()):
            self.db.close()

    def convertToBinaryData(self, file_path):
        # Конвертирование в BLOB
        with open(file_path, 'rb') as file:
            blobData = file.read()
        return blobData


if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    app.setStyle('Fusion')
    w = Storage_app()
    app.exec_()

使用以下方法将数据插入数据库QtSql.QSqlQuery()：

query = QSqlQuery()
query.prepare("INSERT INTO person (id, forename, surname) "
              "VALUES (:id, :forename, :surname)")
query.bindValue(":id", 1001)
query.bindValue(":forename", "Bart")
query.bindValue(":surname", "Simpson")
query.exec_()

问题：如果数据如何插入BLOB？

如果可能的话，一个小例子。我从逻辑上理解需要翻译成什么BLOB，然后插入一个变量......

最小的例子：

from PySide2 import QtSql
import os

def convertToBinaryData(file_path):
    # Конвертирование в BLOB
    with open(file_path, 'rb') as file:
        blobData = file.read()
        print()
    return blobData


def createConnection():
    db = QtSql.QSqlDatabase.addDatabase("QSQLITE")
    db.setDatabaseName("local_base.db")  # !!! .db
    if not db.open():
        print("Cannot establish a database connection")
        return False
    return db

# Получим данные BLOB
# картинка test_BLOB.jpg рядом с файлом скрипта
file_path = (f"{os.getcwd()}\\test_BLOB.jpg")
test_BLOB = convertToBinaryData(file_path)

db = createConnection()
db.transaction()
q = QtSql.QSqlQuery()
q.exec_("DROP TABLE IF EXISTS company;")
q.exec_("CREATE TABLE company ("
        "id INT PRIMARY KEY, "
        "name_company TEXT NOT NULL, "
        "blob_data BLOB NOT NULL );")

# Вставка тестовых значений

query = QtSql.QSqlQuery()
query.prepare("INSERT INTO company (id, name_company, blob_data) "
              "VALUES (:id, :name_company, :blob_data)")
query.bindValue(":id", 1)
query.bindValue(":name_company", 'АО КОПЫТА')
query.bindValue(":blob_data", test_BLOB)
query.exec_()

db.commit()


if __name__ == '__main__':
    print("Запуск")

idname_company它插入底座，但不插入BLOB。

无法运行 Prohorenok 书中的示例。

不会添加或删除行。

也许有人会告诉我或写我自己的，我将非常感激。

from PyQt5 import QtCore, QtWidgets, QtSql
import sys

def addRecord():
    stm.insertRow(stm.rowCount())

def delRecord():
    stm.removeRow(tv.currentIndex().row())
    stm.select()

app = QtWidgets.QApplication(sys.argv)
window = QtWidgets.QWidget()
window.setWindowTitle("QRelationalSqlTableModel")
con = QtSql.QSqlDatabase.addDatabase('QSQLITE')
con.setDatabaseName('data.sqlite')
con.open()
stm = QtSql.QSqlRelationalTableModel(parent = window)
stm.setTable('good')
stm.setSort(1, QtCore.Qt.AscendingOrder)
# Задаем для поля категории связь с таблицей списка категорий
stm.setRelation(3, QtSql.QSqlRelation('category', 'id', 'catname'))
stm.select()
stm.setHeaderData(1, QtCore.Qt.Horizontal, 'Название')
stm.setHeaderData(2, QtCore.Qt.Horizontal, 'Кол-во')
stm.setHeaderData(3, QtCore.Qt.Horizontal, 'Категория')
vbox = QtWidgets.QVBoxLayout()
tv = QtWidgets.QTableView()
tv.setModel(stm)
tv.hideColumn(0)
tv.setColumnWidth(1, 150)
tv.setColumnWidth(2, 60)
tv.setColumnWidth(3, 150)
vbox.addWidget(tv)
btnAdd = QtWidgets.QPushButton("&Добавить запись")
btnAdd.clicked.connect(addRecord)
vbox.addWidget(btnAdd)
btnDel = QtWidgets.QPushButton("&Удалить запись")
btnDel.clicked.connect(delRecord)
vbox.addWidget(btnDel)
window.setLayout(vbox)
window.resize(430, 250)
window.show()
sys.exit(app.exec_())

应该是结果：

请告诉我，显示颜色图如何最好地应用于图像会更好吗？

例如，我有一个 400 x 400 test.png 的图像，我通过 plt 显示它，然后我在 pcolor 上绘制了一个 alpha = 0.25 的颜色图，但它并没有按照我想要的方式进行......图片不清晰可见，连同颜色条（好像它不是一个 Alpha 通道，而是某种混合），加上某种网格 =(

import matplotlib.pyplot as plt
 
image = plt.imread('test.png')
plt.imshow(image)
vals = []
for i in range(0,200):
    if i <50:
        val_list = [2]*200
    elif i <100:
        val_list = [5]*200
    elif i <150:
        val_list = [10]*200
    vals.append(val_list)
plt.pcolor(vals, cmap=plt.get_cmap('jet', 11), alpha = 0.25)
plt.colorbar()
plt.show()

我试着把图片200的大小改成200，不行=(