我需要為我的Reviewers_POS表創(chuàng)建一個外鍵。我將Reviewers_Id作為主鍵，我想將其從Reviewrs_POS表傳遞給我的id_r1。    import MySQLdb as mdb    import sys    conexao = mdb.connect('localhost', 'root', 'rot', 'DbOmelete')    with conexao:      cur = conexao.cursor()   cur.execute("CREATE TABLE IF NOT EXISTS Reviewers(Reviewers_Id int unsigned not null AUTO_INCREMENT, PRIMARY KEY (Reviewers_Id),Title varchar(500), Polarity INT, Review TEXT);")   cur.execute("CREATE TABLE IF NOT EXISTS Reviewers_POS(ReviewersPOS_Id int unsigned not null PRIMARY KEY AUTO_INCREMENT, Review_POS TEXT,id_r1 integer,CONSTRAINT fk_id FOREIGN KEY (id_r1) REFERENCES Reviewers (Reviewers_Id));")__我收到此錯誤：追溯（最近一次通話）：  File "SQLTesteForeign.py", line 14, in <module>    cur.execute("CREATE TABLE IF NOT EXISTS Reviewers_POS(ReviewersPOS_Id int unsigned not null PRIMARY KEY AUTO_INCREMENT, Review_POS TEXT,id_r1 integer,CONSTRAINT fk_id FOREIGN KEY (id_r1) REFERENCES Reviewers (Reviewers_Id) ON DELETE NO ACTION ON UPDATE NO ACTION);")  File "/usr/lib/python2.7/dist-packages/MySQLdb/cursors.py", line 174, in execute    self.errorhandler(self, exc, value)  File "/usr/lib/python2.7/dist-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler    raise errorclass, errorvalue_mysql_exceptions.OperationalError: (1005, "Can't create table 'DbOmelete.Reviewers_POS' (errno: 150)")有人知道如何解決嗎？我以為我想念某物..因為我真的不知道“哪里”是錯誤..