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Is self joining possible in RDM tables ?

  • May 26, 2025
  • 2 replies
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O
Star Blazer L1
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Hello,

Is it possible to self-join tables in RDM to populate some information? I would like to try something like shown in the screenshot. Attribute 4 and 5 values are selected from RDM UI. So, dropdown should only show values from the same table where att2 = CAT2 for Att4 and att2 = CAT3 for Att4

Table1          
      Selection from RDM UI  
Att1 Att2  Att3 Att4 (where att2 = CAT2) Att5 (where att2 = CAT3)  
ID1 CAT1 val1 ID3 ID5  
ID2 CAT1 val2 ID4 ID6  
ID3 CAT2 val3      
ID4 CAT2 val4      
ID5 CAT3 val5      
ID6 CAT3 val6      
           

 

I somehow tried to create self join in relationship like below. I was able toi upload configuration successfully on RDM with these relationships. 

 

However, when edit the record on RDM the lookup is blank. it does not show any value although table is populated.

 

  (this can also be understood as employee info vs manager info relationship. Both info are available in the employee table)

Thanks in advance.

Ojaswini

Best answer by may_kwok

You likely need to set the display mode for Att1 to “label”.

 

Setting the display mode to “label” allows that attribute to be chosen by a child column in the combo box.

Your drop down box looks empty, but it’s actually got all the rows in your table “underneath” it. There likely was no columns set as “label”, and therefore the combo box doesn’t know which column to put as display.

Have a go and see if that works?

Link to the official documentation is here.

 

 

    2 replies

    may_kwok
    Rocket Pioneer L1
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    • may_kwokRocket Pioneer L1
    • Rocket Pioneer L1
    • Answer
    • May 28, 2025

    You likely need to set the display mode for Att1 to “label”.

     

    Setting the display mode to “label” allows that attribute to be chosen by a child column in the combo box.

    Your drop down box looks empty, but it’s actually got all the rows in your table “underneath” it. There likely was no columns set as “label”, and therefore the combo box doesn’t know which column to put as display.

    Have a go and see if that works?

    Link to the official documentation is here.

     

     

      O
      Star Blazer L1
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      • OjaswiniStar Blazer L1
      • Author
      • Star Blazer L1
      • June 3, 2025

      Thank you very much. Yes, ID was set as Normal. Thank you. Oops. I didn't even notice that. 

      Best regards,

      Ojaswini

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