Entity Relationship Diagrams

15 Responses to “Entity Relationship Diagrams”

  1. kyle.arrington October 18, 2016 at 6:00 pm #

    Hi John,

    I’m a bit confused regarding the difference between a zero to many relationship, and an unspecified relationship. Does unspecified just mean more or less “unlisted”? I just don’t know how you would get less specific than zero to many.

    • JohnCoppedge October 19, 2016 at 5:55 pm #

      Good Q Kyle- unspecified means that it hasn’t been outright named in the ERD- but you are right this would typically mean it is a zero to many.

      • kyle.arrington October 21, 2016 at 3:28 am #

        Got it, thank you! It’s really great how responsive you are to the comments here.

  2. flacovy July 16, 2016 at 1:55 pm #

    HI John: after several views of your video I noticed that the section on M:M relationships is missing one key piece of info. The join object (Campaign Member) is missing LeadId. Not sure if you wanted to (or even could fix this) but just FYI.

  3. flacovy July 14, 2016 at 11:07 am #

    Hi John:

    1) Is there a quick way to determine which objects are junction objects – used in many:many relationships? The ERD diagrams are pretty complicated and make it difficult to identify junction objects, at least I think so.
    2) When the cardinality is unspecified, what does that imply? What can I assume the cardinality is for that relationship?
    Thanks for the great content.

    • flacovy July 14, 2016 at 11:17 am #

      John: kinda early in the morning. I figured out answer to my first question. No need to answer question 1. thanks

      • JohnCoppedge August 19, 2016 at 1:36 pm #

        1. schema builder is a good tool
        2. the cardinality in almost all salesforce relationships is one to many

  4. choudhary.saurabh@gmail.com April 11, 2016 at 9:22 pm #

    I just noticed in the SOAP API Developer Guide – Sales Objects that Account to Contract and Account to Order is 1:M, not 0:M. This would mean that there has to be at least a Contract and Order for an Account. That doesn’t make sense. Could you please clarify?

    • JohnCoppedge April 13, 2016 at 8:55 pm #

      I’m sure it’s zero to many – the cardinality isn’t always expressed fully beyond x to many in some erds.

  5. joshirohan27 August 30, 2015 at 7:54 am #

    hi John
    can you plz explain me what is the difference between ‘0 to many’ ans ‘1to many’ relationahips?

    Thanks
    Rohan

    • JohnCoppedge September 1, 2015 at 8:58 pm #

      Depends on the context – are you talking about one side of the relationship or both?

      For example, a one to many relationship typically refers to the entire relationship (e.g. one account can have many contacts). Zero to many is usually a more verbose specification of the ‘many’ side of the relationship (e.g. one account can have ‘zero to many’ contacts). This level of specificity is not really common in Salesforce data models, as most relationships are simply just defined as one to many (where many is defined as ‘zero to many’). Any additional stipulations would need to be added via additional logic (e.g. validation rule) outside of the relationship itself (e.g. if you want to require that an account had at least one contact).

  6. Cloud Force March 18, 2015 at 10:40 am #

    Hi John,
    Hi John,
    1. In the above video, you have mentioned unspecified relationship between a contact and an account objects using the ERD model. Does that mean a contact can be a standalone object i.e. without any relationship with an account object.
    2. If that is the case what is the impact of sharing settings of record(s) related to the contact object if OWD is set to private. Is there any trick or magic there. Please clarify.
    Thanks.

    • JohnCoppedge March 18, 2015 at 10:56 am #

      Yes you can have a contact without an associated account. Contacts by default inherit sharing from the account, so if the account is populated on the contact and the account is private then the contact would be as well (inheriting record access from the account).

  7. Swanand patil March 17, 2014 at 7:16 pm #

    Which documents do you recommend for Entity Relationships?Could you provide the link?
    Thanks,

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