What character is used to exclude a field from a set in LookML?

In LookML, the character used to exclude a field from a set is the hyphen, represented as "-". This operator allows developers to specify a field that should be omitted from the results of a query or a specific set of fields.

When using this character, it effectively modifies the behavior of a field set, ensuring that the excluded field does not appear in the final output that is generated during data querying. This is particularly useful when refining data exploration and visualizations, as it enables clear control over which fields are included in analyses.

Other characters serve different purposes. The plus sign typically indicates inclusion, the exclamation mark is often reserved for logical operations, and the asterisk usually represents a wildcard or all fields rather than exclusion. Hence, the use of the hyphen as the exclusionary character is integral to defining cleaner and more focused datasets within Looker.