# Field Types

To support multiple SQL vendors (MySQL, PostgreSQL, MS-SQL, etc) Directus has a generalized set of field types to define API output (array, json, boolean, etc) and system data (m2o, alias, group, etc).

• alias – Fields that do not have corresponding column in the database
• array – Standard array format in API response
• binary – Binary strings limited by its length
• boolean – true or false
• datetime – A date and time in ISO format, eg: 2018-09-19T14:00:43+00:00
• date – Date, eg: 2018-09-19
• time – Time, eg: 14:09:22
• file – Foreign key to directus_files.id
• group – Groups fields together visually, children save group into directus_fields.group
• hash – Its value gets hashed based on the hasher option. (Default to: password_hash.PASSWORD_DEFAULT)
• integer – Whole number
• decimal – Number that includes a decimal
• json – Standard JSON format in API response
• lang – Specific to translation interfaces, this stores the language key
• m2o – Many-to-One Relationship
• o2m – One-to-Many Relationship
• slug – Removes all the special characters from another field. It will ignore the mirrored field value if the slug already has a value set.
• sort – System field that stores a item order within the collection items
• status – System field used for publishing workflows
• string – Any text or characters, limited by its length
• translation – Specific to translation interfaces, this is a o2m for multi-lingual content
• uuid – A Universally Unique Identifier
• datetime_created – System field to track the datetime an item was created, used by revisions
• datetime_updated – System field to track the datetime an item was updated, used by revisions
• user_created – System field to track the user who created an item, used by revisions
• user_updated – System field to track the user who updated an item, used by revisions