title: How to reference a composite primary key into a single field?
body: <p>I got this composite primary key in Table 1: </p>
  
  <pre><code>Table 1: Applicant
  
  CreationDate PK
  FamilyId PK
  MemberId PK 
  </code></pre>
  
  <p>I need to create a foreign key in Table 2 to reference this composite key. But i do not want to create three fields in Table 2 but to concatenate them in a single field. </p>
  
  <pre><code>Table 2: Sales
  
  SalesId int, 
  ApplicantId  -- This should be "CreationDate-FamilyId-MemberId"
  </code></pre>
  
  <p>What are the possible ways to achieve this ? </p>
  
  <p>Note: I know i can create another field in Table 1 with the three columns concatenation but then i will have redundant info</p>