问题描述
我正尝试将从唯一查询的SELECT
语句中获得的两个数字相乘。我想获取提供者的数量和提案的数量(我进行的查询显示了该数量),然后在同一行上都将它们相乘(我不能这样做)。
我已经为您展示了一个非常简单的示例(如下代码):DEMO ON FIDDLE
创建2个在2个部门工作的提供者:
CREATE TABLE ##Provider
(
id INT,p_name VARCHAR(50),id_dep INT
)
INSERT INTO ##Provider (id,p_name,id_dep) VALUES
(1,'toto',10),(2,11),(3,'tata',9);
在2个部门中创建4个提案:
CREATE TABLE ##Proposal
(
id INT,c_name VARCHAR(50),id_dep INT
)
INSERT INTO ##Proposal (id,c_name,'propA','propB',09),'propC',(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者和建议的数量(实际查询要复杂得多,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
但是我无法显示这两个数字的计算结果:
select
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
我并没有尝试太多,因为我不确定这是否可能...也许我应该使用UNION?
解决方法
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