在嵌套的 SQL 语句中使用 OR 运算符

Question

我有一个包含供应商、他们销售什么以及他们所在位置的数据库。

我需要搜索基于特定地区（例如州）的供应商或以寻找销售一定数量产品的供应商。

这个问题的一个例子是：

What are the full names of all vendors who can supply more than one item or are based in Illinois?

如果我可以使用两个 sql 查询（但对于这个问题我不能），这会很容易。

假设在使用的表之间没有连接，我的解决方案是不正确的，但这是我尝试过的

select 
cs.vendor_id, name, count(cs.PRODUCT_ID) 
from 
grocery.vendor 
where 
va.state_territory_province = 'Illinois' 
group by 
(cs.vendor_id)
or /# error found here #/
having 
(count(cs.product_id)>1);

第 1 行错误： ORA-00933: SQL 命令未正确结束

如果我分别尝试每一个，我会得到这些结果

使用 Illonois

select 
cs.vendor_id, v.name, count(cs.PRODUCT_ID) 
from 
grocery.vendor v 
inner join grocery.vendor_address va 
on (v.vendor_id = va.vendor_id) 
inner join grocery.can_supply cs 
on (v.vendor_id = cs.vendor_id) 
where 
va.state_territory_province = 'Illinois' 
group by 
(cs.vendor_id, v.name);

VENDOR_ID 名称计数(CS.PRODUCT_ID)

33 Drinks R Us                       1
35 Jungle Man                        1
34 Poland Spring                     1

使用产品数量

select 
cs.vendor_id, v.name, count(cs.PRODUCT_ID) 
from grocery.vendor v 
inner join grocery.vendor_address va 
on (v.vendor_id = va.vendor_id) 
inner join grocery.can_supply cs 
on (v.vendor_id = cs.vendor_id) 
group by (cs.vendor_id, v.name) 
having(
count(cs.product_ID)>1);

VENDOR_ID 名称计数(CS.PRODUCT_ID)

 8 Orgo Home Farm                    3
17 Wellness                          2
21 Wily Wonka                        4
27 Camel                             3
29 Supplies R Us                     5
13 Clean Me Please                   5
15 Oral Care Inc                     2
31 Cheese Cake Factory               2
37 Crunchy                           2
 1 Moo Moo Milk Farm                 4
 4 Haagen Daz                        3
26 Beer Inc                          4
 6 Sailor Bob                        3
10 Dawn                              2
16 SPAM                              2
18 Wonder inc                        3
 5 Butcher Mat                       3
 9 Soda Forever                      4
14 Wash Shampoo Inc                  4
24 Huntz                             4
20 Hershey                           3
22 Bake Me Inc                       5
30 We Make Pizza                     2
36 Taste Treat                       3
 7 Monkey Paradise                   6
19 Puff                              5

已选择 26 行。

基本上我想将这两个查询合并为一个。有没有办法将它们嵌套在一起？

Answer 1

您应该能够将两个条件都放在 HAVING 子句中：

select v.vendor_id, 
       v.name, 
       count(cs.PRODUCT_ID) 
  from grocery.vendor v 
  join grocery.vendor_address va 
    on v.vendor_id = va.vendor_id
  join grocery.can_supply cs 
    on v.vendor_id = cs.vendor_id
 group by v.vendor_id, v.name, va.state_territory_province
having va.state_territory_province = 'Illinois'
    or count(cs.product_ID) > 1

正如评论中指出的那样，我不能只在 HAVING 子句中使用 va.state_territory_province（愚蠢的我），所以我将其添加到 GROUP BY 子句中。我假设每个供应商只有一个地址。

Answer 2

如何为两个查询使用 UNION 子句？

Answer 3

我倾向于这样做：

select v.*
from gorcery.vendor v join
     grocery.vendor_address va
     on v.vendor_id = va.vendor_id
where va.state_territory_province = 'Illinois' or
      (select count(*)
       from grocery.can_supply cs 
       where v.vendor_id = cs.vendor_id
      ) > 1;

注意：这并不完美，因为供应商可以有多个地址。所以，我认为更好的解决方案是：

select v.*
from gorcery.vendor v
where exists (select 1
              from  grocery.vendor_address va
              where v.vendor_id = va.vendor_id and
                    va.state_territory_province = 'Illinois'
             ) and
      (select count(*)
       from grocery.can_supply cs 
       where v.vendor_id = cs.vendor_id
      ) > 1;

在嵌套的 SQL 语句中使用 OR 运算符

Using the OR operator in a nested SQL Statement

sql

oracle

having

where-clause