一個(gè)查詢樹狀結(jié)構(gòu)的語句
SELECT 1,LEVEL,LNAME,NULL,CODE
FROM PRDGP CONNECT BY PRIOR CODE = P_CODE
START WITH P_CODE IS NULL
說明:P_CODE為父級(jí),CODE為子集,P_CODE為空時(shí)為樹的最頂級(jí),即為Start with 起點(diǎn),遞歸方式為CODE = P_CODE,LEVEL為樹的等級(jí)
SELECT CODE,LNAME,CNAME
FROM PRDGP WHERE CODE <> 'LBL' AND TYPE= 'GMT' CONNECT BY PRIOR CODE=PARENTGRP AND PARENTGRP <> 'LBL'
START WITH PARENTGRP IS NULL ORDER BY CODE