pb中(+)是什么意思？

[HOI]

请教！！： WHERE B.user_id(+) = A.user_id
这里面的(+) 是什么意思啊？？？请教

SELECT source_id,count(DISTINCT A.user_id) user_cnt,sum(fee_noenough) noenough,sum(fee_nopay) nopay,sum(fee_paid) paid,sum(fee_noenough)+sum(fee_nopay)+sum(fee_paid) total_fee
FROM ((SELECT user_id,
sum(decode(fee_kind,198,abs(fee1+fee2+fee3+fee4+fee11+fee12+fee13+fee14),0)) fee_noenough,
sum(fee1+fee2+fee3+fee4+fee11+fee12+fee13+fee14) fee_nopay,
0 fee_paid
FROM "BF_BILL_T"
WHERE user_id > 0
AND fee_date = :v_fee_date
AND city_code = :v_city_code
AND service_kind = :v_service_kind
GROUP BY user_id)
UNION
(SELECT user_id,
0 fee_noenough,
0 fee_nopay,
ABS(sum(fee1)) fee_paid
FROM "BF_BILL_PAY_T"
WHERE user_id > 0
AND fee_date = :v_fee_date
AND city_code = :v_city_code
AND service_kind = :v_service_kind
AND fee_kind IN (198,199)
and pay_date <= :pay_date
GROUP BY user_id
)) a,bb_service_relation_t b,bd_county_dealer_t c
WHERE B.user_id(+) = A.user_id
AND C.city_code (+) = B.city_code
AND C.dealer_id (+) = B.source_id
AND (nvl(B.serving_status,1) <> 9)
AND B.city_code = :v_city_code
AND (:v_innet_date1 = '*' OR (to_char(B.apply_start_date,'yyyymmdd') >= :v_innet_date1
AND to_char(B.apply_start_date,'yyyymmdd') <= :v_innet_date2))
AND (:v_flag = 0 OR (A.fee_nopay + A.fee_paid + A.fee_noenough >= :v_bill_fee1
AND A.fee_nopay + A.fee_paid + A.fee_noenough <= :v_bill_fee2))
GROUP BY source_id

[HOI]

谢谢！！感恩！明白！

[qqqdong]

应该是右连接的意思
检索出右边数据库中所有的数据

[nthb2001]

right join

[gungod2000]

右连接

[IronPromises]

你用的后台数据库是Oracle。
(+)是Oracle中间的外联接符号。

你的一整串SQL的意思是将A这个结果集做为主表去外联接bb_service_relation_t这个表，而bb_service_relation_t又去外联接bd_county_dealer_t这个表。

[scottwhb]

up

[HOI]

感谢，请问，外连接和一般的连接有什么不一样吗？谢谢

[zhouweiwansui]

WHERE B.user_id = A.user_id检索出的数据必须要A，B表中的USERID相对应，就是说如果B表中有ID ‘A’，而A表中没有这个ID，那么这条数据不能检索出，而WHERE B.user_id(+) = A.user_id不管A表中有没有这个ID都读出B表中全部数据