Where子句基于SQL Server中的另一个查询

Question

I have 3 tables in my database called Jobs, JobApplications, Candidates.

here they are.

Jobs

JobId  | JobTitle
    ---------------------------
    2115   | Software Engineer
    2154   | Accountant
    4562   | Sales Manager
    4569   | Civil Engineer

JobApplications

JobApplicationId  | CandidateId | JobId
    ---------------------------
    8845              | 1120        | 2154
    8912              | 1120        | 4569        
    9120              | 1555        | 2115
    9450              | 1899        | 2115
    9458              | 1991        | 4569
    9488              | 1889        | 4569

Candidates

CandidateId | Email
    ----------------------------
    1120        | can1@mail.com
    1555        | can2@mail.com
    1889        | can3@mail.com
    1991        | can4@mail.com

What I want: A table with candidates and jobIds based on their previous applications.
Ex: if someone has applied for the "software engineer" job position, I need the all other jobs with title "software engineer" except the applied job to a table along with candidateId.

Is there any way to achieve this using SQL?

Can anybody help me?

The expected output would be like below

CandidateId | Suggest_jobId
    ------------------------------
    1120        | 3565
    1120        | 8956
    1120        | 4565
    1889        | 8965
    1889        | 4568

So single candidate may have multiple job suggestions.

Answer 1

We can make use of a simple CTE to do the job

 WITH cte AS 
 (
     SELECT j.JobId,
            j.JobTitle,
            ja.CandidateId 
     FROM JobApplications ja
     JOIN Jobs j ON j.JobId=ja.JobId  
 )
 SELECT j.JobTitle,
        c.CandidateId 
 FROM Jobs j
 JOIN cte c ON j.JobTitle like CONCAT('%',c.JobTitle,'%') AND c.JobId!=j.JobId

Answer 2

I have simple and basic solution for you. I have used table function to split applied jobs first. Then I used these results to find similarity using Sanal Sunny's script.

The table function creation script:

CREATE  FUNCTION [dbo].[Tbl_Fn_Split](
    @InputText VARCHAR(8000) 
  , @Delimiter VARCHAR(8000) = ' ' -- delimiter that separates items
) RETURNS @List TABLE (Result VARCHAR(8000))

BEGIN
DECLARE @aResult VARCHAR(8000)
WHILE CHARINDEX(@Delimiter,@InputText,0) <> 0
BEGIN
    SELECT
        @aResult=RTRIM(LTRIM(SUBSTRING(@InputText,1,CHARINDEX(@Delimiter,@InputText,0)-1))),
        @InputText=RTRIM(LTRIM(SUBSTRING(@InputText,CHARINDEX(@Delimiter,@InputText,0)+LEN(@Delimiter),LEN(@InputText))))

    IF LEN(@aResult) > 0
        INSERT INTO @List SELECT @aResult
    END

    IF LEN(@InputText) > 0
        INSERT INTO @List SELECT @InputText 

    RETURN

END

The finding similarity script which is based on Sanal Sunny's answer:

 WITH cte AS 
 (
     SELECT j.JobId,
            j.JobTitle,
            ja.CandidateId,
            A.Result
     FROM JobApplications ja
     JOIN Jobs j ON j.JobId=ja.JobId  
     CROSS APPLY (SELECT * FROM DBO.[Tbl_Fn_Split](j.JobTitle,' ')) A
 )
 SELECT DISTINCT c.CandidateId
        ,j.JobId
        ,j.JobTitle
 FROM Jobs j
 JOIN cte c ON j.JobTitle LIKE '%'+c.Result+'%'AND c.JobId!=j.JobId