如何将数据库中的值插入到我的条目中？ Tkinter

Question

I don't know what I'm doing wrong when I'm trying to insert some values from my database to my entries. I have a main interface with the same code working well, but I've created a secondary window and tried to make work almost the same code but it's not working. It gives me this error:

sqlite3.OperationalError: incomplete input

This is my code:

myid = StringVar()
myname = StringVar()
myowner = StringVar()
mycel = StringVar()

id_entry = Entry(windows2, textvariable=myid)
name_entry = Entry(windows2, textvariable=myname)
owner_id = Entry(windows2, textvariable=myowner)
cel_id = Entry(windows2, textvariable=mycel)

btn_search = Button(windows2, text='SEARCH', command=lambda: search())
btn_search.place(x=930, y=12, width='60', height='26')

def search():

    conn = sqlite3.connect('db1.db')
    c = conn.cursor()
    c.execute("SELECT * FROM regis WHERE idcard=" + myid.get())

    theuser = c.fetchall()

    for user in theuser:
        myid.set(user[0])
        myname.set(user[1])
        myowner.set(user[8])
        mycel.set(user[9])

    conn.commit()

    if theuser:
       messagebox.showinfo(title='ID Found', message='User found')

    else:
       messagebox.showerror(tittle=None, message='Wrong ID')

Answer 1

Explanation:

What you should be doing is adding a master argument to ALL tkinter widgets. When we create Tk() , it creates a tcl interpreter. Each tcl interpreter has its own memory for its widgets. So when you say StringVar() , it doesn't know which tcl interpreter to belong to, so it implicitly uses the first created Tk() . But the first created Tk() might not hold the widget you are associating your StringVar to(with textvariable ), so it will not have its value stored.

Solution:

What you can do is, either explicitly mention which instance of Tk() to belong to, or use Toplevel() for the creation of child windows(like mention by acw1668).

StringVar(master=newwindow) # Same with other tkinter variables and all widgets too

or

newwindow = Toplevel() # Recommended because tkinter was made to work like this?

Also make sure to sanitize your inputs so it wont be prone to SQL injections:

c.execute("SELECT * FROM regis WHERE idcard=?",(myid.get(),))

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Though I would never use StringVar for entry widgets as long as I have to use trace on them. They have their own get() method which works the same way.