sql - 右外连接没有得到相同的结果不知道为什么 (=*)

Question

大家好，数据库外连接和内连接的所有新手都修改了下面的代码

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  

到

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

但是查询没有得到相同的结果，你能帮帮我吗

Answer 1

INNER JOIN 或 JOIN 或 , :

• 给我所有 leaf_star_stem_bud，其中有 leaf_star_item 与之关联。

---

RIGHT JOIN 或 RIGHT OUTER JOIN:

• 给我所有 leaf_star_stem_bud，其中有 leaf_star_item 与之关联。
• 如果还有更多 leaf_star_item，请给我它们并用 null 完成 leaf_star_stem_bud 信息。

---

LEFT JOIN 或 LEFT OUTER JOIN:

• 给我所有 leaf_star_stem_bud，其中有 leaf_star_item 与之关联。
• 如果还有更多 leaf_star_stem_bud，请给我它们并用 null 完成 leaf_star_item 信息。

---

更多信息:

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

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