oracle高效分頁查詢 oracle怎么實(shí)現(xiàn)多表連接查詢并分頁?
oracle怎么實(shí)現(xiàn)多表連接查詢并分頁?oracle使用rownum偽列可以實(shí)現(xiàn)分頁,三表連接分頁示例代碼如下:select * from (select rownum r,k.kch,k.kcm,c
oracle怎么實(shí)現(xiàn)多表連接查詢并分頁?
oracle使用rownum偽列可以實(shí)現(xiàn)分頁,三表連接分頁示例代碼如下:
select * from (select rownum r,k.kch,k.kcm,cj.cj,x.xh,x.xm from KCB k,CJB cj,XSB x where k.kch = cj.kch and cj.xh = x.xh and rownum<=10) where r>0
特別注意這樣外層查詢時(shí)由于內(nèi)層查詢的字段有重復(fù)列名,所以內(nèi)層查詢最后不要用*。取完每一個(gè)表字段,這樣很容易報(bào)錯(cuò)(“無效字段”)
請問各位DBA大佬,SQL如何進(jìn)行多對多表的統(tǒng)計(jì)排序分頁查詢?
以oracle為例:
SELECT * FROM
(
SELECT A.*, ROWNUM RN
FROM (SELECT rs.student_id,count(1) FROM relationship rs group by rs.student_id order by count(1) desc) A
WHERE ROWNUM <= 10
)
WHERE RN >= 0