Create Association
An association is the fundamental building block that is used for describing relationships in the Entity Data Model (EDM). In a conceptual model, an association represents a relationship between two entity types such as a customer and an order. In an application, an instance of an association represents a specific association such as an association between an instance of a customer and an instance of an order. Association instances are logically grouped in an association set.
An association definition contains the following information:
• A unique name (required)
• Two association ends, one for each entity type in the relationship (required)
An association cannot represent a relationship among more than two entity types. An association can, however, define a self-relationship by specifying the same entity type for each of its association ends.
• A referential integrity constraint (optional)
Each association end must specify an association end multiplicity that indicates the number of entity type instances that can be at one end of the association. An association end multiplicity can have a value of one (1), zero or one (0..1), or many (*). Entity type instances at one end of an association can be accessed through navigation properties or foreign keys if they are exposed on an entity type.
Use the Create Association action to create an association between two entity types.
Complete the following steps to use the Create Association action in your workflow:
1. Drag the Create Association action under OData to the canvas, place the pointer on the action, and then click 
or double-click the action. The Create Association window opens.
or double-click the action. The Create Association window opens.2. Edit the Label, if needed. By default, the label name is the same as the action name.
3. To add an OData connector type, refer to Supported OData Connector Types.
If you previously added a connector type, select the appropriate Connector Type, and under Connector Name, select the connector.
4. Click TEST to validate the connector.
5. Click MAP CONNECTOR to execute the action using a connector that is different from the one that you are using to populate the input fields. In the Runtime Connector field, provide a valid OData connector name. For more information about MAP CONNECTOR, see Using Map Connector.
6. In the Select Entity Set list, select an entity set.
7. In the Entity ID field, provide the entity ID.
8. In the Select Association list, select the required association. The association is the containment or non-containment navigation property of the specified entity. If the containment navigation property has a containment navigation property under it, you can select the nested containment navigation property to create the association.
The fields in the input form change dynamically based on the association that you select.
9. Select Form to provide inputs for individual properties, supported navigation properties, and containment navigation properties listed in the form, or select Assign JSON to specify a single JSON with all properties, supported navigation properties, and containment navigation properties.
If the type of navigation property is an entity type, provide a single identifier. If the type of navigation property is a collection of an entity type, provide a comma-separated list of identifiers.
10. Click Show additional fields.
11. Under the Headers group, click Add to add a custom header to the request. Provide a Key and Value pair.
Click Add to add multiple key-value pairs. Click 
to delete any custom header that you added.
to delete any custom header that you added.12. Click Done.
Output schema
The output schema for the Create Association action returns a message attribute.
