Creating A Multi-Select Structure
If you want to create a many-to-many relationship between objects, OneData provides you an easy to use interface through multi-select constructs.
For more information about the structure of a multi-select construct, see
Multi-Select Structure and
Linkages.
Use the example scenario given here to follow the steps in this task.
Example scenario: Create new objects: 'ms_sd_country_state', which holds the many-to-many relationship between the 'ms_sd_state' and 'ms_sd_country' entities. Create a Logical column in the 'ms_sd_country' object that will display a multi-select box showing the list of Countries and States
ms_sd_country_state | ms_sd_state | ms_sd_country |
Country_ID | State_ID | Country_ID |
State_ID | State_Name | Country_Name |
| | State_ID |
To create a multi-select structure
1. On the Menu toolbar, click Define > objects.
2. Click Add Data Object and complete the fields to create ms_sd_country_state.
3. Similarly, create the three objects ms_sd_state, and ms_sd_country.
4. Define the object properties:
a. While defining the ms_sd_country_state entity, create two foreign key constraints, one on Country_ID to the ms_sd_country object, and the other on State_ID to the ms_sd_state object. Display the Country and State Names, and show as Lookup.
b. For the ms_sd_country entity: while defining the State_ID column, select Yes in Is Logical Column?.
c. In the multi-select table, select ms_sd_country_state.
d. In the multi-select column, select State_ID and click Save.
e. In the ms_sd_state object, create a foreign key constraint on State_ID. Display the State Name and show as Lookup.
5. Navigate to Data Manager.
6. ms_sd_country is now configured to show the states as a multi-select box. Since the logical column was configured as “Yes”, the multi-select box is available upon Insert and Edit of Countries and mappings can be managed by using the Display Values > Linkages command. If the logical column were configured as a Linkages Attribute, the multi-select mapping would only be visible from the Linkages command and not upon Insert or Edit.
Note:
To display country name instead of country ID in the Linkages mapping screen, select the Is Description Column? for the Country_Name column.