我正试图将从一个唯一查询的SELECT
语句中得到的两个数字相乘。我想得到提供者的数量和提议的数量(我所做的查询显示了这一点(,并在同一行上相乘(我做不到(。
我做了一个非常简单的例子向您展示(代码如下(:演示FIDDLE
创建2个在2个部门工作的提供商:
CREATE TABLE ##Provider
(
id INT,
p_name VARCHAR(50),
id_dep INT
)
INSERT INTO ##Provider (id, p_name, id_dep) VALUES
(1, 'toto', 10),
(2, 'toto', 11),
(3, 'tata', 9);
创建4个关于2个部门的提案:
CREATE TABLE ##Proposal
(
id INT,
c_name VARCHAR(50),
id_dep INT
)
INSERT INTO ##Proposal (id, c_name, id_dep) VALUES
(1, 'propA', 10),
(2, 'propB', 09),
(3, 'propC', 10),
(4, 'propD', 10);
创建部门表:
CREATE TABLE ##Department
(
id INT,
d_name VARCHAR(50)
)
INSERT INTO ##Department (id, d_name) VALUES
(9, 'dep9')
,(10, 'dep10')
,(11, 'dep11');
在这里,我可以按部门显示提供商和提案的数量(真正的查询要复杂得多,所以我想保留2个子请求(:
select
id,
d_name,
nb_provider = (
SELECT COUNT(DISTINCT Id)
FROM ##Provider p
WHERE p.id_dep = dep.id
),
nb_proposal = (
SELECT COUNT(DISTINCT Id)
FROM ##Proposal pp
WHERE pp.id_dep = dep.id
)
from ##Department dep
WHERE dep.id = 10
但我无法显示这两个数字的计算结果:
select
id,
d_name,
nb_provider = (
SELECT COUNT(DISTINCT Id)
FROM ##Provider p
WHERE p.id_dep = dep.id
),
nb_proposal = (
SELECT COUNT(DISTINCT Id)
FROM ##Proposal pp
WHERE pp.id_dep = dep.id
),
calcul = (nb_provider * nb_proposal) --> DOESN'T WORK
from ##Department dep
WHERE dep.id = 10
我没有尝试太多,因为我不确定这是否可能。。。也许我应该使用UNION?
我建议横向连接:
select
d.id,
d.d_name,
p.nb_provider,
pp.nb_proposal
(p.nb_provider * pp.nb_proposal) calcul
from ##department d
outer apply (
select count(distinct id) nb_provider
from ##provider p
where p.id_dep = d.id
) p
outer apply (
select count(distinct id) nb_proposal
from ##proposal pp
where pp.id_dep = d.id
) pp
where d.id = 10