Example Student Apprenticeship - Adding Constraints
Article Index
Example Student Apprenticeship
City of Residence
Apprenticeship
Generate Expressions
Adding Constraints
Transform to relational
Generating DDL
All Pages

Adding Constraints

After the initial qualification of expressions we've now build up the repository, but there's not a single constraint declared yet. In the diagram we can now select the roles and place different types of constraints.

Unique constraints

  • Student: 'Firstname, Lastname'
  • City: 'City name'
  • Apprenticeship Preference: 'Student, Number'
  • Apprenticeship Preference: 'Student, Apprenticeship'
  • Apprenticeship: 'Apprenticeship Code'
  • etc...

Totality constraints

  • Student: 'City of Residence'
  • Apprenticeship: 'Apprenticeship City'
  • Apprenticeship: 'Apprenticeship Description'
  • City (This constraint means that the population of city must be filled with occurrences from 'City of Residence' and/or 'Apprenticeship City' and nothing else.)

Value Constraints

  • Number: '1, 2, 3'

After placing all the constraints the previously created diagram will be automatically updated with this new information.




 

Add comment


Security code
Refresh

Casetalk Logo

CaseTalk Sponsors

dmz

16-18 Oct, DMZ US

22-23 Oct, DMZ EU

Read More...

Share