Usage
conditionally_filter: {
filters: [field_name: "filter expression", field_name: "filter expression", …]
unless: [field_name, field_name, …]
}
}
Hierarchyconditionally_filter |
Default ValueNoneAcceptsOne or more filter specifications of a field name and a Looker filter expression, plus a list of one or more field names in theunless section
|
Definition
The conditionally_filter
parameter lets you define a set of default filters that users can override if they apply at least one filter from a second list that you define.
This parameter is typically used to prevent users from accidentally creating very large queries that may be too expensive to run on your database. For example, you might force a user to limit their query to the previous week, unless they’ve explicitly asked for a larger date range.
Filters applied in conditionally_filter
appear to the user after they have run their query. While users can change the default value
that you set, they cannot completely remove the filter unless they apply at least one of the filters you specify in the unless
subparameter.
The field names you use can be the name of a dimension
or measure
.
To reference a dimension or measure that is part of a joined view rather than part of this Explore, use view_name.field_name
.
Examples
Consider the following example:
In this case the id
filter refers to the id
field from the Explore called order
. The customer.id
filter refers to the id
field from the view called customer
. Both filters will be applied unless the user sets an order date in the Explore UI. This example also demonstrates that you can require multiple filters.
The default value that you specify can accept these types of expressions.
You can also force the user to use an Order ID filter (with a default value of “123” that they can change) unless they apply an Order Date filter:
Alternatively, force the user to use an Order ID filter (with a default value of “123” or “234” that they can change) unless they apply an Order Date or Order Time filter:
Or, force the user to use an Order ID filter (default value of “123”) and a Customer City filter (with default of “Chicago”), unless they apply an Order Date or Customer Date filter:
Common challenges
A user cannot remove every filter when conditionally_filter
is used
There is no way to run a query without any filters when conditionally_filter
is used. A user must use the conditional filters you specify, or their own filters from the unless
list.
conditionally_filter
with a dimension of type: time
in a group puts the group’s other dimensions in the unless
subparameter
If the field
you specify within conditionally_filter
is a time-based dimension that is part of a dimension group, then Looker will treat all of that group’s other dimensions as if they were subject to an unless
subparameter for that conditional filter — even if you don’t include an unless
subparameter.
The following two blocks of LookML are interpreted identically. Here, conditionally_filter
is applied to a time-based dimension event_date
that is part of the event
dimension group. No unless
conditions are specified, but Looker will treat the other dimensions in the event
group as though they had been specified with the unless
subparameter.
LookML block 1:
LookML block 2:
Looker interprets the two LookML blocks the same way, even though only the second LookML block explicitly applies the unless
subparameter to the event
group’s other dimensions.
Things to know
There is a method to apply conditionally_filter
to a subset of users
To apply a conditional filter for some users but not others, you can use model permissions. You need to create two models: one in which conditionally_filter
is used, and one in which it is not. You can then grant access to the proper models on a user-specific basis.
If you want to use conditionally_filter
without unless
, just use always_filter
instead
To force users to use a specific set of filters no matter what, but let them change the default value, use always_filter
instead.
If you want filters that cannot be changed at all, consider sql_always_where
If you want an Explore to have filters that are the same for everyone, and not let the users change the filter value, use sql_always_where
.
If you want user-specific filters that cannot be changed, consider access_filter
If you want an Explore to have filters that are specific to each user, but cannot be removed or changed, use access_filter
.