我正在觀看 Udacity 課程中的視頻，并在嘗試通過 psycopg2 運(yùn)行 SQL 命令時(shí)遇到錯(cuò)誤。該代碼與講師的相同，但我的返回錯(cuò)誤而她的沒有。import psycopg2# establish connection to dbconnection = psycopg2.connect('dbname=example')# cursor is essentially an interface that allows you to start# cuing up work and transactionscursor = connection.cursor()# defines SQL transactioncursor.execute('''    CREATE TABLE table2 (        id INTEGER PRIMARY KEY,        completed BOOLEAN NOT NULL DEFUALT False    );''')cursor.execute('INSERT INTO table2 (id, completed) VALUES (1, true);')# commits the transactionconnection.commit()# must manually close your session each time one is openedconnection.close()cursor.close()錯(cuò)誤：$ python3 demo.pyTraceback (most recent call last):  File "demo.py", line 11, in <module>    cursor.execute("""psycopg2.errors.SyntaxError: syntax error at or near "DEFUALT"LINE 4:         completed BOOLEAN NOT NULL DEFUALT False