grid > source > query > select > join > columns

The <columns> element wraps all the columns to be selected from a joined table that was specified with the <join table=”…”> element.

It takes zero or more <column> or <expression> child elements.

(Note: the <columns> element nested under <join> works the same as the <columns> element that is nested under <select>).

If no join <columns> are configured, no columns will be included in the result set from the joined table (this is different from the default <select> columns).

Example:

<columns>
    <column name="status" as="order_status"/>
    <expression as="count">COUNT(*)</expression>
</columns>