How do I create a Many-to-Many Doctype mapping

1

Hello Everyone,

I have a usecase where I need to have many-to-many mapping between 2 Doctypes as follows:

  • I have 2 Doctypes Plan & Control (It is many to many because many Controls can map to multiple Plans and vice versa)
  • I want to be able to create a Plan with(out) a Control and vice versa.

How can I implement this?

Note: I already explored using child table and creating intermediate table (with link types) but they dont fit my use case. With intermediate Doctypes I get an error that I am not sure how to fix as shown below.

image
image1912×290 25.3 KB

2

For creatimg many to one fields in Frappe you had to use link fieldtype and in option select the doctype from which you had to join the other table/doctype.

3

Hello @Mohtashim_Shoaib ,

Thanks for your answer, but I want a Many-to-Many not Many-to-One for this example.

For the case you mentioned, I currently just use the Doctype Link feature and that works ok for me.

4

Child tables with linking doctypes is indeed the correct way do many-to-many. I don’t know what’s going on with the error you’re showing, and it’s hard to say much more without context.

5

Yes, you can do with child table this thing but its depend on your use case which is best fit in your scenario.

6

@peterg Do you know how the Customer - Address & Contact relationship is defined?
That is exactly the type of mapping that I am looking for.

About the Child table and linking doctype option, but I will investigate the current error and see if there is a way to provide more context.

7

The Address and Contact interfaces on the Customer doctype uses a custom HTML field with doctype-specific javascript.

The actual data representation is managed by a child table with a linking doctype, like what I’m describing in my last post (the links child table in the Address or Contact doctype).

8

Thanks for that clarification, I found what I did wrong, I went to the child Table (Control Details) and set the Naming rule to be fieldName:[field], so that made the link field have the same value as the default primary key field of name, which obviously has a unique constraint in the DB.

For the sake of information for anyone else that is looking for a similar solution, these are my steps.

I did the following:

  • Created the Plan Doctype and the Control Doctype as standalone types
  • Then I created a Control Details is_child Doctype with a single link field to Control Doctype. Make sure that you dont change the default Settings for Naming.
1 Like