sql自增列问题，求大大解答

Question

mysql建立一个自增列，初始为1，新建一个记录，其值为2，如果删除掉这条记录，那么下次新建的记录值是2还是3，如果是2，怎么是sql新建的记录值跳过原有的值呢

Answer 1

不知道你有没有试过，删除所有数据，再插入时id是3，但清空数据表时，再插入又是从1开始的。你可以每次删除某条记录是，重新排序一下，给你一个存储过程看一下
1、传参：传递两个参数进去，每次删除数据时调用一次
CREATE DEFINER=root@localhost PROCEDURE reorder(IN tablename CHAR(50), IN orderid CHAR(50))
LANGUAGE SQL
NOT DETERMINISTIC
CONTAINS SQL
SQL SECURITY DEFINER
COMMENT ''
BEGIN
set @tab=tablename;
set @id=orderid;
set @aa:=concat("ALTER TABLE ",@tab," drop " , @id);
set @bb:=concat("ALTER TABLE ",@tab," ADD ", @id," INT( 8 ) NOT NULL FIRST;");
set @cc:=concat("ALTER TABLE ",@tab," MODIFY COLUMN ",@id," INT( 8 ) NOT NULL AUTO_INCREMENT,ADD PRIMARY KEY(",@id,")");
prepare pa from @aa;
prepare pb from @bb;
prepare pc from @cc;
execute pa;
execute pb;
execute pc;
END

2、静态不含参
CREATE DEFINER=root@localhost PROCEDURE reset()
LANGUAGE SQL
NOT DETERMINISTIC
CONTAINS SQL
SQL SECURITY DEFINER
COMMENT ''
BEGIN
ALTER TABLE user DROP useid;
ALTER TABLE user ADD useid INT( 8 ) NOT NULL FIRST;
ALTER TABLE user MODIFY COLUMN useid INT( 8 ) NOT NULL AUTO_INCREMENT,ADD PRIMARY KEY(useid);
END