避免重复输入mysql数据库的最佳方法

第一步是在表上设置唯一键：

ALTER TABLE thetable ADD UNIQUE INDEX(pageid, name);

然后，当有重复项时，您必须决定要做什么。你应该：

1. 忽略它？

   INSERT IGNORE INTO thetable (pageid, name) VALUES (1, "foo"), (1, "foo");

2. 覆盖先前输入的记录？

   INSERT INTO thetable (pageid, name, somefield)

   VALUES (1, “foo”, “first”)
   ON DUPLICATE KEY UPDATE (somefield = ‘first’)
   

   INSERT INTO thetable (pageid, name, somefield)
   VALUES (1, “foo”, “second”)
   ON DUPLICATE KEY UPDATE (somefield = ‘second’)
   

3. 更新一些柜台？

   INSERT INTO thetable (pageid, name)

   VALUES (1, “foo”), (1, “foo”)
   ON DUPLICATE KEY UPDATE (pagecount = pagecount + 1)