Primary Foreign relation in ACM

Forum|Forum|5 years ago
August 10, 2020
2 replies
2206 views

Hi Experts,

If I understand correctly, if we declare a key in adobe data schema, it creates an unique index with not null constraint enforced in the backend table (not exactly an Oracle primary key).

I'm trying to implement Primary-Foreign key relation in ACM. I've declared a link between the tables (code below).
However, it doesn't enforce this in backend database (parent-child validations don't take place).
Sample code below:

Scenario: Parent table (test1) & child table (test2). Sample below:

test1:

<element label="test1" name="test1">

   <key internal="true" name="PKEY_t1">
     <keyfield xpath="@col1"/>
   </key>

   <attribute label="col1" name="col1" type="long"/>
   <attribute label="col2" name="col2" type="string"/>
   <attribute label="col3" name="col3" type="string"/>
</element>

test2:

<element label="test2" name="test2">

   <key internal="true" name="PKEY_t2">
     <keyfield xpath="@col1"/>
   </key>

   <attribute label="col1" name="col1" type="long"/>
   <attribute label="col2" name="col2" type="long"/>
   <attribute label="col3" name="col3" type="string"/>

   <element label="test_link" name="test_link" target="pl_:test1" type="link">
   <join xpath-dst="@col1" xpath-src="@col2"/>
   </element>

</element>

Please suggest.

This post is no longer active and is closed to new replies. Need help? Start a new post to ask your question.

Best answer by Milan_Vucetic

Hi @abhiseks1679239

define cardinality in the link according to your use case.

Find the Links: relation between tables section here: link

Regards,

Milan

Milan_VuceticAccepted solution

Level 9

Hi @abhiseks1679239

define cardinality in the link according to your use case.

Find the Links: relation between tables section here: link

Regards,

Milan

A

abhiseks1679239Author

Level 2

@milan_vuceticHi, after i created the tables...below was what got created:

Parent - pl_:test1

<element label="test2" name="test2-test_link" revLink="test_link" target="pl_:test2"
             type="link" unbound="true">
      <join xpath-dst="@col2" xpath-src="@col1"/>
</element>

Child - pl_:test2

<element label="test_link" name="test_link" revLink="test2-test_link"
     target="pl_:test1" type="link">
    <join xpath-dst="@col1" xpath-src="@col2"/>
</element>

I believe this was 1-1 cardinality which is created by default? Even so, i was able to insert a record in child table (test2), which didn't exist in parent table(test1). hence, my doubts.

If it's possible, can you give me an example of how you'd define a link of cardinality 1-N.

Thank you