from PyQt5.QtWidgets import QApplication from PyQt5.uic import loadUi import pymysql class Stats: def init(self): # 从文件中加载UI定义 # 从 UI 定义中动态创建一个相应的窗口对象 # 注意：里面的控件对象也成为窗口对象的属性了 # 比如 self.ui.button , self.ui.textEdit self.ui = loadUi("Form - untitled.ui") # 信号和槽 self.ui.login.clicked.connect(self.handleCalc) def handleCalc(self): hostaddr = self.ui.hostaddr.text() username = self.ui.username.text() password = self.ui.password.text() database = self.ui.database.text() tablename = self.ui.tablename.text() con = connect(hostaddr,username,password,database,tablename) con.connect_to_database() # 连接数据库 # con = pymysql.connect(host=hostaddr, # user=username, # password=password, # database=database, # charset='utf8mb4', # ) # cur = con.cursor() # statement = "select * from {table} where id=1".format(table=tablename) # cur.execute(statement) # data = cur.fetchone() # print(data) # con.close() class connect: def init(self,hostaddr,username,password,database,tablename): self.hostaddr=hostaddr self.username=username self.password=password self.database=database self.tablename=tablename def connect_to_database(self): con = pymysql.connect(host=self.hostaddr, user=self.username, password=self.password, database=self.database, charset='utf8mb4', tablename=self.tablename, ) cur = con.cursor() statement = "select * from {table} where id=1".format(table=tablename) cur.execute(statement) data = cur.fetchone() print(data) con.close() if name == 'main': app = QApplication([]) stats = Stats() stats.ui.show() app.exec_()修改一下

代码中的错误：

1. connect_to_database() 方法中，使用了变量 tablename，但是应该使用 self.tablename。

2. 在主函数的 if name == 'main' 中，没有加上模块名，应该是 if __name__ == '__main__'。

修改后的代码如下：

from PyQt5.QtWidgets import QApplication
from PyQt5.uic import loadUi
import pymysql

class Stats:
    def __init__(self):
        # 从文件中加载UI定义
        # 从 UI 定义中动态创建一个相应的窗口对象
        # 注意：里面的控件对象也成为窗口对象的属性了
        # 比如 self.ui.button , self.ui.textEdit
        self.ui = loadUi("Form - untitled.ui")

        # 信号和槽
        self.ui.login.clicked.connect(self.handleCalc)

    def handleCalc(self):
        hostaddr = self.ui.hostaddr.text()
        username = self.ui.username.text()
        password = self.ui.password.text()
        database = self.ui.database.text()
        tablename = self.ui.tablename.text()

        con = connect(hostaddr,username,password,database,tablename)
        con.connect_to_database()

class connect:
    def __init__(self,hostaddr,username,password,database,tablename):
        self.hostaddr=hostaddr
        self.username=username
        self.password=password
        self.database=database
        self.tablename=tablename

    def connect_to_database(self):
        con = pymysql.connect(host=self.hostaddr, user=self.username, password=self.password, database=self.database, charset='utf8mb4')
        cur = con.cursor()
        statement = "select * from {table} where id=1".format(table=self.tablename)
        cur.execute(statement)
        data = cur.fetchone()
        print(data)
        con.close()

if __name__ == '__main__':
    app = QApplication([])
    stats = Stats()
    stats.ui.show()
    app.exec_()