我正在使用Oracle SQL Developer来运行我的查询。
我在Oracle数据库中有两个表。见下文。
table_1
------------------------------------------------------
SKU | MAIN_LOCATION | BACKUP_LOCATION
------------------------------------------------------
111 | 05-AA | 09-DD
222 | 02-BB | 10-JJ
333 | 07-CC | 13-LL
444 | 06-HH | 19-PP
table_2
---------------------------------------------
SKU | QUANTITY | LOCATION
---------------------------------------------
111 | 5 | 05-AA
111 | 8 | 09-DD
222 | 2 | 02-BB
333 | 4 | 07-CC
444 | 1 | 06-HH
444 | 11 | 19-PP
555 | 16 | 21-UU
我需要什么
我需要的是一个查询,显示table_1
上的所有SKU(每行一个SKU),以及根据table_2
位置的列数量。如果备份位置中没有提供数据,那么我只想显示一个空值。我需要的例子如下。
QUERY NEEDED
---------------------------------------------------------------------------
SKU | MAIN_LOC | MAIN_LOC_QTY | BACKUP_LOC | BACKUP_LOC_QTY
---------------------------------------------------------------------------
111 | 05-AA | 5 | 09-DD | 8
222 | 02-BB | 2 | 10-JJ | (null)
333 | 07-CC | 4 | 07-CC | (null)
444 | 06-HH | 1 | 19-PP | 11
我尝试过什么
我首先运行了一个查询,以确保我能够从table_1
提取所需的所有SKU。
SELECT table_1.sku AS SKU,
table_1.main_location AS MAIN_LOC
FROM table_1
没问题。
然后我将table_2
添加到查询中,甚至没有添加任何列,只是为了确保我获得的SKU行数量与之前的查询相同,这不起作用。见下文。
SELECT table_1.sku AS SKU,
table_1.main_location AS MAIN_LOC
FROM table_1,
table_2
WHERE table_1.sku = table_2.sku(+)
这是我开始遇到问题的时候;如果SKU存在于table_2
中的两行,那么它在我的查询中显示为两行,如下所示:
SKU | MAIN_LOC
--------------------
111 | 09-DD
111 | 09-DD
222 | 02-BB
333 | 07-CC
444 | 06-HH
444 | 06-HH
我需要上面的每个SKU仍然只显示一行。
假设上述查询甚至有效,我仍然试图根据位置获取数量信息,如下所示:
SELECT table_1.sku AS SKU,
table_1.main_location AS MAIN_LOC,
CASE
WHEN table_1.main_location = table_2.location THEN table2.quantity
ELSE NULL
END AS MAIN_LOC_QUANTITY,
table_1.backup_location AS BACKUP_LOC,
CASE
WHEN table_1.backup_location = table_2.location THEN table2.quantity
ELSE NULL
END AS BACKUP_LOC_QUANTITY
FROM table_1,
table_2
WHERE table_1.sku = table_2.sku(+)
加入/外连接(+)
是获得我需要的所有SKU的唯一方法,但仍然最终获得相同SKU的重复行(这是我不想要的)。
我甚至试图在FROM
语句中创建一个子查询来减少我不需要的一些SKU,如下所示:
SELECT table_1.sku AS SKU,
table_1.main_location AS MAIN_LOC,
CASE
WHEN table_1.main_location = sub_table.location THEN sub_table.quantity
ELSE NULL
END AS MAIN_LOC_QUANTITY,
table_1.backup_location AS BACKUP_LOC,
CASE
WHEN table_1.back_location = sub_table.location THEN sub_table.quantity
ELSE NULL
END AS BACKUP_LOC_QUANTITY
FROM table_1,
(
SELECT *
FROM table_2
WHERE location NOT LIKE '%[SOME CONDITIONS]%'
) sub_table
WHERE table_1.sku = table_2.sku
这产生与先前查询几乎相同的结果。它摆脱了我不需要的一些东西,但没有解决主要问题。
我还在绝望中添加了一些我对连接/外连接知之甚少的内容:
WHERE table_1.sku(+) = table_2.sku
以及:
WHERE table_1.sku = table_2.sku(+)
但是在这一点上,我认为我只是抓住吸管而且我自己充斥着太多我不知道的东西。
我的问题
A)我无法弄清楚如何让MAIN_LOC_QTY
列根据Table 2
数据显示数量。
B)当来自Table 1
的SKU存在于两行Table 2
上时,我的查询为一个SKU生成两行,当我只需要一行存在与该SKU有关的所有信息时。
任何帮助将不胜感激。谢谢!
我的解决方案(2014年2月2日更新)
对于遇到此问题的人,我的解决方案由Brian Demilia提供。基本上,我的查询如下;
SELECT table_1.sku, --This is from table_1
table_1.main_location, --This is from table_1
main_loc.quantity, --This is from the 1st LEFT JOIN named main_loc
table_1.backup_location, --This is from table_1
backup_loc.quantity --This is from the 2nd LEFT JOIN named backup_loc
FROM table_1
/*LEFT JOIN below is to make table_2 with only the main_location from table_1*/
LEFT JOIN table_2 main_loc
ON table_1.main_location = main_loc.location
AND table_1.sku = main_loc.sku
/*LEFT JOIN below is to make table_2 with only the backup_location from table_1*/
LEFT JOIN table_2 backup_loc
ON table_1.backup_location = backup_loc.location
AND table1.sku = backup_loc.sku
我希望以上帮助遇到此问题的其他人。感谢所有回复。
- 安东尼
答案 0 :(得分:3)
select t1.sku,
t1.main_location,
ml.quantity as main_qty,
t1.backup_location,
bl.quantity as bkup_qty
from table_1 t1
left join table_2 ml
on t1.sku = ml.sku
and t1.main_location = ml.location
left join table_2 bl
on t1.sku = ml.sku
and t1.backup_location = bl.location
order by t1.sku