# on¶

## Description¶

on is a special function used to specify the join condition for some verbs in the join category (for example, join and leftjoin).

joinpredicate

## Domain¶

This is a scalar function (calculates a single output value for a single input row.)

## Usage¶

on( expr )


Argument

Type

Required

Multiple

expr

bool

Required

Only one

## Examples¶

join on(same(container_id, @container.id)), name:@container.name


Perform an inner-join between the default input of the verb and input @container based on the condition that the default input’s column container_id must contain the same value as the other input’s id column. Because same is used to compare the two columns, a null container_id can also join with a null id from the other input.

join on(value > @right.min and value < @right.max), name:@right.name


Perform an inner-join between the default input of the verb and input @right based on the condition value must be within the range defined by min and max.