MySQL Displays line numbers, and group sort

Build table:

CREATE TABLE' MY_TB ' (' ID ')int( One) not NULLauto_increment, ' Parent_code 'varchar(255)DEFAULT NULL, ' Code 'varchar(255)DEFAULT NULL,  PRIMARY KEY(' id ')) ENGINE=InnoDB auto_increment=8 DEFAULTCHARSET=UTF8;

Initial data:

INSERT  into' My_tb ' (' Parent_code ', ' Code ')VALUES(' on','001');INSERT  into' My_tb ' (' Parent_code ', ' Code ')VALUES(' on','002');INSERT  into' My_tb ' (' Parent_code ', ' Code ')VALUES(' Geneva','001');INSERT  into' My_tb ' (' Parent_code ', ' Code ')VALUES(' on','003');INSERT  into' My_tb ' (' Parent_code ', ' Code ')VALUES(' Geneva','002');INSERT  into' My_tb ' (' Parent_code ', ' Code ')VALUES('Geneva','001');INSERT  into' My_tb ' (' Parent_code ', ' Code ')VALUES('Geneva','001');

Query line number:

-- Generate line Numbers Select @r:=@r+1 as Row_num, a.* from  My_tb A, (select@r:=0) b

Show group number:

--Generating grouping sort numbersSelect       @group_row:= Case  when @parent_code=A.parent_code Then  @group_row+1 Else 1 End  asGrouprow,@parent_code:=A.parent_code asParent_code, A.code fromMy_tb A, (Select @group_row:=1,@parent_code:="') asbORDER  byA.parent_code, A.code

MySQL Displays line numbers, and group sort