如何在Tkinter中传递变量

Question

server = 'svr'
database = 'db'
username = 'sa'
password = 'password' 

   connection = pyodbc.connect(
        'DRIVER={ODBC Driver 13 for SQL Server};SERVER=' + server + ';DATABASE=' + database + ';UID=' + username + ';PWD=' + password)


if connection:
    print("Connection to [", database, "] was successful.\n")

cur = connection.cursor()

root = Tk()
root.title = "Scrap Report"
root.geometry = '400x400'

lb1 = Label(root, text='Enter JobNo')

lb1.pack()

txt1 = Text(root, height=2, width=10)
txt1.pack()
mainloop()

ESTIMATED LABOR COST
cur.execute(''' ... +JobNo+... ''')

data = cur.fetchall()
totLabor = 0
for row in data:
    totLabor += row[0]
print(totLabor, 'Labor Cost')

我是一个巨大的蟒蛇新手，我已经研究了几种不同的方法，并且每次都没有成功。我知道tkinter代码很粗糙，每次变量传递不成功时我都会继续根除它。我需要将txt1用户条目传递给变量JobNo，运行SQL查询，然后打印结果。我不确定Text()电话是否正确。 JobNo变量是str()。如果需要，我可以提供更多信息。