Mysql数据库就是这样的;
userID -> primaryKey, required, unsigned integer, auto increment, unique
usermail -> unique,varchar,required
我正在创建新用户。userId 是自动递增的。如果之前插入了usermail,则会发生错误。我的问题是这个
Let's think that userID is between 1-9.(there are 9 users now).
Somebody has inserted same usermail before and took error.
After that,new user inserted another usermail but userID became 11 instead 10.
Why? What should i do to make it 10?