Using sql across multiple threads Python

Question

I have a server which allows (admins) to create,remove or edit other user's details, I have created the database alongside its cursors inside a function:

def DBSetup():
    global schoolDBConn, schoolDBCursor
    print("Setting up databases")
    schoolDBConn = sqlite3.connect("SCHOOL_DB.db")
    schoolDBCursor = schoolDBConn.cursor()
    schoolDBCursor.execute(
                            """
                               CREATE TABLE IF NOT EXISTS USER_DETAILS 
                               (
                               username text,
                               password text,
                               clearance int,
                               classes int
                               )
                            """
                            )
    schoolDBCursor.execute(   #line 300
                            """
                            CREATE TABLE IF NOT EXISTS CLASSES  
                            (
                            className text,
                            supervisor text,
                            assignmentName text
                            )
                            """
                            )
    schoolDBCursor.execute(
                            """
                            CREATE TABLE IF NOT EXISTS ASSIGNMENT 
                            (
                            setDate text,
                            dueDate text,
                            assignmentInfo text,
                            supervisor text
                            )  
                            """
                             )

I call this when the server starts up, and then I begin my thread:

if __name__ == "__main__":
    DBSetup()
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    s.bind((host, port))
    s.listen(1)
    while True:
        conn, addr = s.accept()
        connThread = Thread(target=handler, args=(conn, addr))
        connThread.daemon = True
        connThread.start()

However inside my thread, whenever I use a function that edits the database, i get this error:

SQLITE3 ERROR:

SQLite objects created in a thread can only be used in that same thread.The object was created in thread id 9628 and this is thread id 12400

I am using global locks in my program "With global_lock:" whenever I edit a database.

Thank you in advance

Answer 1

You could set the check_same_thread parameter to false. Like this in your case:

schoolDBConn = sqlite3.connect("SCHOOL_DB.db", check_same_thread=False)

From the docs:

By default, check_same_thread is True and only the creating thread may use the connection. If set False , the returned connection may be shared across multiple threads. When using multiple threads with the same connection writing operations should be serialized by the user to avoid data corruption.