TreeView header text update with each new SQL query-CodePudding

I am required to build a very simple database app where I can run MySQL queries and show them on the screen. I am using tkinter TreeView for this purpose;

root = Tk()
root.title("Database Access")
root.geometry("1280x720")
mycursor = db.cursor()

input1 = Entry(root, width=100)
input1.pack()

columns1 = ['111', '222', '333', '444', '555', '666', '777', '888']
tree = ttk.Treeview(root, columns=columns1, show='headings')

tree.heading('#1', text=columns1[0])
tree.heading('#2', text=columns1[1])
tree.heading('#3', text=columns1[2])
tree.heading('#4', text=columns1[3])
tree.heading('#5', text=columns1[4])
tree.heading('#6', text=columns1[5])
tree.heading('#7', text=columns1[6])
tree.heading('#8', text=columns1[7])

tree.pack(expand=True)

And I defined a submit button so whenever the user writes a query, the resulting table can be shown in treeview;


def submit():
    mycursor.execute(input1.get())
    result = mycursor.fetchall()

    first_data = map(lambda x: x[0], mycursor.description)
    columns1.clear()
    for i in first_data:
        columns1.append(i)
        # stuck here ===============
    root.update()
    print(columns1) # it prints the correct new values but now shown in headers
        
    for row in result:
        tree.insert('', 'end', values=row[0:8])

buttonSubmit = Button(root, text="SUBMIT QUERY", width=50, command=submit)
buttonSubmit.pack()

The problem is I can't get the column headers in the window to updated.

If I even re-configure tree headings right after #stuck here# like exactly as before;

tree.heading('#1', text=columns1[0])
tree.heading('#2', text=columns1[1])
tree.heading('#3', text=columns1[2])
tree.heading('#4', text=columns1[3])
tree.heading('#5', text=columns1[4])
tree.heading('#6', text=columns1[5])
tree.heading('#7', text=columns1[6])
tree.heading('#8', text=columns1[7])

It begins to write the new headers but crashes when it fails to find a value in the corresponding column as expected because not all query results are exactly 8 columns long.

IndexError: list index out of range

After a long search I couldn't figure out how to hold a placeholder in the tree headings in a healthy convenient way so I can pass new header names easily.

Hope it is clear. I'm new to programming but other simple approaches are also welcome.

CodePudding user response：

You need to update columns option of tree and the headings inside submit(). Also you can simply use mycursor.column_names:

def submit():
    mycursor.execute(input1.get())
    result = mycursor.fetchall()

    tree.config(columns=mycursor.column_names)
    for col in mycursor.column_names:
        tree.heading(col, text=col)

    for row in result:
        tree.insert('', 'end', values=row)