2014-09-01 68 views
2

大家好新的數據庫外連接和內連接修改下面的代碼從右外連接沒有得到相同的結果不知道爲什麼(= *)

FROM leaf_star_stem_bud, leaf_star_item, cosmic_tank 
WHERE leaf_star_stem_bud.power_company_key = '6aa5' 
     And leaf_star_item.parent_key = 'eaab1' 
     And cosmic_tank.master_key = leaf_star_item.cost_code_key 
     And leaf_star_stem_bud.parent_key =* leaf_star_item.master_key 

FROM leaf_star_stem_bud 
    RIGHT OUTER JOIN leaf_star_item ON 
    leaf_star_stem_bud.parent_key = leaf_star_item.master_key , cosmic_tank 
WHERE leaf_star_stem_bud.power_company_key = '6aa5' 
     And leaf_star_item.parent_key = 'eaab1' 
     And cosmic_tank.master_key = leaf_star_item.cost_code_key 

但查詢沒有得到相同的結果,能否請你幫我出

+0

如果您使用加入,你必須參加所有列。不要混合加入,並在那裏爲''cosmic_tank使用 – Jens 2014-09-01 06:43:12

+0

適當INNER JOIN語法'cosmic_tank'以及 – cha 2014-09-01 06:43:16

+0

仁則說,他們語法的修改是做 – user2045810 2014-09-01 06:45:32

回答

1

INNER JOINJOIN

  • 給我你所有leaf_star_stem_bud具有leaf_star_item與其關聯。

RIGHT JOINRIGHT OUTER JOIN

  • 給我你所有leaf_star_stem_bud具有leaf_star_item與其關聯。
  • 如果有更多的leaf_star_item,給我他們和完整leaf_star_stem_bud與信息。

LEFT JOINLEFT OUTER JOIN

  • 給我你所有leaf_star_stem_bud具有leaf_star_item與其關聯。
  • 如果有更多的leaf_star_stem_bud,給我他們和完整leaf_star_item信息。

欲瞭解更多信息:

What is the difference between Left, Right, Outer and Inner Joins?

http://en.wikipedia.org/wiki/Join_(SQL)

相關問題