SQL查询，不显示所有记录

Question

我有一个查询的问题，比如这一个我可以检索记录：

SELECT 
l.*, 
ll.f_cocacola as cocacola, 
le.name AS deposit, 
lp.price 
FROM 
KPC AS l, 
KPC_cocacola AS ll, 
KPC_deposit AS le, 
KPC_price AS lp 
WHERE 
l.cod_deposit = le.id_deposit 
AND l.code = ll.code 
AND lp.code = l.code 
AND l.code_deposit = '002365' 

，但现在我需要包括从另一个表的另一日期-intranet-具有领域代码和网址则需要从该表中网址秀场..记住，我们的关系就代码场。

，所以我更改查询，以这样的方式

SELECT l.*,ll.f_cocacola as cocacola, le.name AS deposit, 
lp.price, lintranet.url 
FROM tableX AS l, intranet_cocacola AS ll, tableX_deposit AS le, 
tableX_price AS lp, 
tableX_intranet as lintranet 
WHERE l.code_deposit = le.id_deposit 
AND l.code = ll.code 
AND lp.code = l.code 
AND l.code = lintranet.code 
AND l.code_deposit = '456852147' 

但问题是，一些记录没有网址，如果不存在网址那么这个查询不告诉我的记录..以及我所需要的，即使没有一个URL关联到我希望看到recorda的记录，由于

Answer 1

使用ANSI连接语法和使用LEFT JOIN重写查询什么更好的画面：

SELECT l.*, ll.f_cocacola as cocacola, le.name AS deposit, 
     lp.price, lintranet.url 
FROM tableX AS l, 
JOIN intranet_cocacola AS ll 
ON  ll.code = l.code 
JOIN tableX_deposit AS le 
ON  le.id_deposit = l.code_deposit 
JOIN tableX_price AS lp 
ON  lp.code = l.code 
LEFT JOIN 
     tableX_intranet as lintranet 
ON  lintranet.code = l.code 
WHERE l.code_deposit = '456852147' 

Answer 2

使用LEFT JOIN代替：

SELECT l.*,ll.f_cocacola as cocacola, le.name AS deposit, 
lp.price, lintranet.url 
FROM tableX AS l, intranet_cocacola AS ll, tableX_deposit AS le, 
tableX_price AS lp 
LEFT JOIN tableX_intranet as lintranet ON l.code = lintranet.code -- <<<<< 
WHERE l.code_deposit = le.id_deposit 
AND l.code = ll.code 
AND lp.code = l.code 
AND l.code_deposit = '456852147' 

PS：我个人更喜欢明确的INNER JOIN，而不是使用逗号分隔的表枚举连接。因为它给出了查询确实

Answer 3

我知道你已经有一个答案，但我看到你的问题用Oracle数据库制作......而我认为LEFT JOIN的作品，因为它是STANDAR SQL，Oracle有它自己的版本，所以你可以看到这个相同的查询写成如下：

SELECT l.*,ll.f_cocacola as cocacola, le.name AS deposit, lp.price, lintranet.url 
    FROM tableX AS l, intranet_cocacola AS ll, tableX_deposit AS le, tableX_price AS lp, tableX_intranet as lintranet 
WHERE l.code_deposit = le.id_deposit 
    AND l.code = ll.code 
    AND lp.code = l.code 
    AND l.code_deposit = '456852147' 
    AND l.code = lintranet.code(+) //<-- this is how a left/right join is written 
            //on Oracle's SQL, you add "(+)" next to the 
            //field of the table that may not have 
            //matching records.