MySQL 给数据排序同时追加序号列

• 无分组

  select @rownum:=@rownum+1 as autoSeq,
  sid,pid,oprimary,seq
  from singlechoice,(select @rownum:=0) r
  order by pid,sid

• 单字段分组

  select (@i := case  when  @tableName=a.tablename then @i + 1 else 1 end )  as rowIndex,
  a.*,(@tableName:=a.tablename)
  from tablestyle a,(select @i:=0,@tableName:='') as t
  group by tablename,fieldname
  order by tablename,(@i := case  when  @tableName=a.tablename then @i + 1 else 1 end )

• 多字段分组

  select (@i := case  when  @tableName=concat(a.dbname,a.tablename) then @i + 1 else 1 end )  as rowIndex,
  a.*,(@tableName:=concat(a.dbname,a.tablename)) as temp
  from tablestyle a,(select @i:=0,@tableName:='') as t
  group by dbname,tablename,fieldname
  order by dbname,tablename,(@i := case  when  @tableName=concat(a.dbname,a.tablename) then @i + 1 else 1 end )