A multi-select construct in OneData provides a visual representation for managing many-to-many relationships between objects. Move data into the multi-select box using the arrows. OneData manages the insert or delete of the corresponding rows in the many-to-many relationship table.

Multi-select constructs are configured with logical columns, which do not hold values, but exist to define the relationship. These relationships can then be viewed and maintained in the Manage Data module. The multi-select box will be shown when using the Edit or Insert command for individual values, and also upon selecting the Linkages command and using the mapping grid to manage many values at once. If the Logical Column is defined as a Linkages Attribute, the many-to-many relationship is managed via the Linkages command only. Alternate values can also be assigned using the grid.

An example model of a multi-select construct is shown below. In this example, the ms_sd_country_state (relationship) table is the relationship between ms_sd_state and ms_sd_country. The ms_sd_country table (main or multi-select table) contains the logical column and multi-select relationship on the State ID.

If the object where the multi-select construct or Linkages Attribute is defined contains a two-part primary key, the physical column names must be the same in the multi-select table and the relationship table. Using the example above, if the ms_sd_country object contains a two-part primary key on State ID and Country ID, and the ms_sd_country_state table contains a two-part primary key on State ID and Country ID, the primary key physical column names must be the same for both objects. (For example: State_ID and Country_ID).

In the object where the logical column exists (either Yes for Logical Column or Linkages Attribute), both the multi-select table and multi-select column must be mapped to the object containing multiple values in order to create the Multi-Select Construct correctly. Using the above example, the ms_sd_country table holds the logical column. The multi-select table is ms_sd_country_state and the multi-select column is state_ID. If the logical column is marked as Linkages Attribute and the multi-select table and column are not selected, that column is excluded from the query, as well as hidden from the interface in Data Manager (like logical column).