SQL Server 中具有多个限定条件筛选器的搜索引擎答案

【问题标题】：Search Engine with Multiple Qualification Filters in SQL ServerSQL Server 中具有多个限定条件筛选器的搜索引擎
【发布时间】：2021-05-10 17:54:36
【问题描述】：

我正在尝试构建一个类似于求职门户网站的搜索引擎。我的查询与资格特别相关。我的最终用户可以查询具有单个或一组资格-学科组合的员工，或者他们可以提供具有学科的资格列表并询问所有完成任何给定资格-学科组合的员工。我的脚本如下。

declare @Qualification table(QualId int identity primary key, Qualification varchar(100))
declare @Discipline table(DispId int identity primary key, Discipline varchar(100))
declare @Emp table(Eid int identity primary key, EName varchar(100))
declare @EmpQualification table(Eid int, QualId int, DispId int)
declare @ReqData table(QualId int, DispId varchar(100))
declare @AllMandatory char(1)

insert into @Qualification
select 'Diploma' union
select 'B.E' union
Select 'MBA' union
select 'MCA' union
Select 'B.Sc' union
Select 'B.Com'

insert into @Discipline
select 'HR' union
select 'IT' union
Select 'Computers' union
select 'Agriculture' union
Select 'Civil'

insert into @Emp
select 'SANTHOSHANAND M' union
select 'VENKATA VEERA JAGADEESH MANNE' union
select 'E.SURESH KUMAR' union
select 'E HARIHARA PUTHIRAN' union
select 'SOUMYAJIT MOHANTY' union
select 'TANMOY DAS' union
select 'PANAKANTI SANTHOSH' union
select 'G NAVEEN KUMAR' union
select 'VIJAY LOGANATHAN' union
select 'SAI KIRAN GANDHE'

INSERT INTO @EmpQualification
SELECT 1,1,3 UNION
SELECT 1,5,4 UNION
SELECT 2,2,2 UNION
SELECT 2,6,3 UNION
SELECT 3,3,3 UNION
SELECT 3,2,3 UNION
SELECT 4,4,2 UNION
SELECT 4,2,3 UNION
SELECT 5,5,4 UNION
SELECT 5,3,1 UNION
SELECT 6,6,3 UNION
SELECT 6,4,3 UNION
SELECT 7,1,3 UNION
SELECT 7,5,5 UNION
SELECT 8,2,3 UNION
SELECT 8,6,3 UNION
SELECT 9,3,1 UNION
SELECT 9,1,3 UNION
SELECT 10,4,5 UNION
SELECT 10,2,5 

SELECT e.Eid, E.EName Name, ql.Qualification, d.Discipline FROM @Emp E
INNER JOIN @EmpQualification Q ON E.Eid = Q.Eid
INNER JOIN @Qualification QL ON Q.QualId = QL.QualId
INNER JOIN @Discipline D ON Q.DispId = D.DispId

insert into @ReqData
select 1,'Any' union
select 5,4

set @AllMandatory = 'N'

if @AllMandatory = 'N'
select * from @Emp where Eid in (
select distinct q.Eid from @EmpQualification q
inner join (select distinct QualId, convert(int,DispId) DispId from @ReqData where DispId <> 'Any') f on q.QualId = f.QualId and q.DispId = f.DispId
union
select distinct q.Eid from @EmpQualification q
inner join (select distinct QualId from @ReqData where DispId = 'Any') f on q.QualId = f.QualId)
--else
-- My recursive procedure goes here, which consumes lot of time

我的用户查询示例如下。

这将出现在我的@ReqData 表中，如下所示

符合所有上述标准的所有员工。这是通过我的@AllMandatory 变量捕获的

set @AllMandatory = 'Y'

上面的查询应该给我所有从事 B.Com 的任何学科的员工，并且还获得了人力资源方面的 MBA 学位。以下应该是查询结果

Eid EName
1   E HARIHARA PUTHIRAN

假设同一张@ReqData表，如果@AllMandatory设置为N，则结果应该如下，即所有做过B.Com的员工，或者所有做过B.Com的员工做过MBA HR。

Eid EName
1   E HARIHARA PUTHIRAN
5   SAI KIRAN GANDHE
7   SOUMYAJIT MOHANTY
9   VENKATA VEERA JAGADEESH MANNE

@ReqData 有时可能有 50 到 60 行。为了实现这一点，我只能使用循环或存储过程递归。我有大约 50,000 名员工和大约 2,00,000 个资格，而且还在不断增长。因此，这种循环和递归使我的系统变慢。有没有更好更简单的方法来解决这个问题？真的可以用一个查询来处理吗？

【问题讨论】：

仅供参考，自 2008 年（甚至可能是 2005 年）以来，SQL Server 就支持插入的 VALUES 子句。不再需要那些昂贵的UNION（或更便宜的UNION ALL）查询了。
"我的用户查询示例如下"。该示例是结果集，而不是查询。我很困惑。
我的最终用户在前端选择所需的资格和学科，我发布的图像实际上是他们看到的，它是如何进入SQL server的就是我的@ReqData表。
你有20000000000个资格？请不要使用诸如“十万”之类的印度词。我们并不都来自印度
见伟大的 Joe Celko 的 Divided We Stand: The SQL of Relational Division

标签： sql sql-server multi-query

【解决方案1】：

我找到了一种无需循环或递归即可实现此目的的解决方案。在下面发布解决方案。谢谢大家的帮助。

declare @Qualification table(QualId int identity primary key, Qualification varchar(100))
declare @Discipline table(DispId int identity primary key, Discipline varchar(100))
declare @Emp table(Eid int identity primary key, EName varchar(100))
declare @EmpQualification table(Eid int, QualId int, DispId int)
declare @ReqData table(QualId int, DispId varchar(100))
declare @AllMandatory char(1)
declare @CriteriaCnt int

insert into @Qualification
select 'Diploma' union
select 'B.E' union
Select 'MBA' union
select 'MCA' union
Select 'B.Sc' union
Select 'B.Com'

insert into @Discipline
select 'HR' union
select 'IT' union
Select 'Computers' union
select 'Agriculture' union
Select 'Civil'

insert into @Emp
select 'SANTHOSHANAND M' union
select 'VENKATA VEERA JAGADEESH MANNE' union
select 'E.SURESH KUMAR' union
select 'E HARIHARA PUTHIRAN' union
select 'SOUMYAJIT MOHANTY' union
select 'TANMOY DAS' union
select 'PANAKANTI SANTHOSH' union
select 'G NAVEEN KUMAR' union
select 'VIJAY LOGANATHAN' union
select 'SAI KIRAN GANDHE'

INSERT INTO @EmpQualification
SELECT 1,1,3 UNION
SELECT 1,5,4 UNION
SELECT 2,2,2 UNION
SELECT 2,6,3 UNION
SELECT 3,3,3 UNION
SELECT 3,2,3 UNION
SELECT 4,4,2 UNION
SELECT 4,2,3 UNION
SELECT 5,5,4 UNION
SELECT 5,3,1 UNION
SELECT 6,6,3 UNION
SELECT 6,4,3 UNION
SELECT 7,1,3 UNION
SELECT 7,5,5 UNION
SELECT 8,2,3 UNION
SELECT 8,6,3 UNION
SELECT 9,3,1 UNION
SELECT 9,1,3 UNION
SELECT 10,4,5 UNION
SELECT 10,2,5 

SELECT e.Eid, E.EName Name, ql.Qualification, d.Discipline FROM @Emp E
INNER JOIN @EmpQualification Q ON E.Eid = Q.Eid
INNER JOIN @Qualification QL ON Q.QualId = QL.QualId
INNER JOIN @Discipline D ON Q.DispId = D.DispId

insert into @ReqData
select 2,2 union
select 6,3

select @CriteriaCnt = count(QualId) from @ReqData

set @AllMandatory = 'N'

if @AllMandatory = 'N'
select * from @Emp where Eid in (
select distinct q.Eid from @EmpQualification q
inner join (select distinct QualId, convert(int,DispId) DispId from @ReqData where DispId <> 'Any') f on q.QualId = f.QualId and q.DispId = f.DispId
union
select distinct q.Eid from @EmpQualification q
inner join (select distinct QualId from @ReqData where DispId = 'Any') f on q.QualId = f.QualId)
else
begin
select em.* from @Emp em
inner join
(select h.Eid, count(h.QualId) Cnt from 
(select distinct q.Eid, f.QualId from @EmpQualification q
inner join (select distinct QualId, convert(int,DispId) DispId from @ReqData where DispId <> 'Any') f on q.QualId = f.QualId and q.DispId = f.DispId
union
select distinct q.Eid, f.QualId from @EmpQualification q
inner join (select distinct QualId from @ReqData where DispId = 'Any') f on q.QualId = f.QualId) h
group by h.Eid
having count(h.QualId) >= @CriteriaCnt) m on m.Eid = em.Eid
end

【讨论】：