> For the complete documentation index, see [llms.txt](https://docs.mashmatrix.com/mashmatrix-sheet/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.mashmatrix.com/mashmatrix-sheet/functions_advanced/union_sheet/add_and_configure_columns.md).

# Add and Configure Columns

In a union sheet, you can add columns and change their settings in the same way as in an ordinary sheet. However, an operation to specify which object's field the column displays is added. For the terms union column, single-source column, and source object, see "[Overview](/mashmatrix-sheet/functions_advanced/union_sheet/overview.md)".

## Add Column <a href="#add-column" id="add-column"></a>

To add a column to a union sheet, follow the procedure below.

1. Select "Add Column" from the column header menu.
2. The "Object" selector is displayed in "Field Column" of the "Add Column" dialog. Select the object that has the field you want to add.
3. From the displayed list of fields, select the field to add as a column.
4. Click the "Add" button at the bottom right of the dialog.

<figure><img src="https://2214743720-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FOYt1c4qdNlLlHO5tcs5o%2Fuploads%2FaRjtpBNNP8ffMe13L4hA%2FCleanShot%202026-08-26%20at%2008.41.42%402x.png?alt=media&amp;token=46747782-29fb-4b29-b148-e78e3c96bc51" alt=""><figcaption></figcaption></figure>

A column added by this procedure becomes a single-source column that displays only the field of the selected object.

## Change to a Union Column <a href="#convert-to-union-column" id="convert-to-union-column"></a>

By assigning a field of another object to an existing column, you can make it a union column that unites fields of multiple objects into a single column.

To make a single-source column a union column, follow the procedure below.

1. Select "Setting" from the column header menu of the target column.
2. In "Reference Field" of the "Basic Property" tab of the "Edit Column Setting" dialog, the assignment for each united object is displayed as a list. "(None)" is displayed for an object to which no field is assigned.
3. Click the edit button ("Select Field") on the right side of "(None)".
4. The "Select Field" dialog is displayed. Select the field to assign.
   * You can narrow down the fields by entering a keyword in the search box.

<figure><img src="https://2214743720-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FOYt1c4qdNlLlHO5tcs5o%2Fuploads%2FOyv2uJyFtcmO9sZjojRB%2FCleanShot%202026-08-26%20at%2008.44.02%402x.png?alt=media&amp;token=4532d3aa-b2e7-459f-8cff-44226a450f18" alt=""><figcaption></figcaption></figure>

### Assignable Fields <a href="#assignable-fields" id="assignable-fields"></a>

Only the fields that can be assigned to the column are displayed in the "Select Field" dialog. To be assignable, a field must have a data type compatible with the data type of the column.

Text, textarea, URL, phone, and email types are compatible data types with each other, but all other data types must be fields of the same data type.

## Column Settings per Source Object <a href="#column-setting-per-source" id="column-setting-per-source"></a>

In a union column, some of the settings are specified per source object.

The "Source Object" selector is displayed in the "Options" tab of the "Edit Column Setting" dialog. When you select an object here, the settings for that object are displayed and can be changed.

The settings specified per source object and those common to the whole column are as follows.

<table data-search="false"><thead><tr><th>Setting</th><th>Unit</th></tr></thead><tbody><tr><td>"Set the Cells to be Editable"</td><td>Per source object</td></tr><tr><td>"Require Value Input"</td><td>Per source object</td></tr><tr><td>Edit settings of each edit control</td><td>Per source object</td></tr><tr><td>Auto fill</td><td>Per source object</td></tr><tr><td>"Use as Key to Identify Record"</td><td>Common to the whole column</td></tr><tr><td>Picklist options</td><td>Common to the whole column</td></tr><tr><td>Summary display setting</td><td>Common to the whole column</td></tr></tbody></table>

Picklist options are common to the whole column, but only the values valid for the object of that row are displayed as options when editing a cell.

{% hint style="info" %}
Whether a cell can be edited is determined not only by the setting here, but also by the field access permission on Salesforce for the object of that row and by the access control setting of the administration console. For details, see "[Access Control](/mashmatrix-sheet/settings_for_admin/administration_console/access_control.md)".
{% endhint %}