mysql 遞歸排序查詢

備注：producttype  排序表，producttype。ptype父節點  ，producttype 。id 主鍵，showTreeNodes (IN rootid INT) 函數，參數為起始類型rootid.

drop PROCEDURE IF EXISTS  showTreeNodes;

CREATE PROCEDURE showTreeNodes (IN rootid INT)
BEGIN
DECLARE Level int ;
drop TABLE IF EXISTS tmpLst;
CREATE TABLE tmpLst (
  id int,
  nLevel int,
  sCort varchar(8000)
);
Set Level=0 ;
INSERT into tmpLst SELECT id,Level,ID FROM producttype WHERE ptype=rootid;
WHILE ROW_COUNT()>0 DO
  SET Level=Level+1 ;
  INSERT into tmpLst
   SELECT A.ID,Level,concat(B.sCort,A.ID) FROM producttype A,tmpLst B
    WHERE  A.ptype=B.ID AND B.nLevel=Level-1  ;
END WHILE;
END;
CALL showTreeNodes(-1);

SELECT concat(SPACE(B.nLevel*2),'┕',A.name)
FROM producttype A,tmpLst B
WHERE A.ID=B.ID
ORDER BY B.sCort;