Adds a unique constraint for one or more columns.

The constraint name can be anything you want, but it must be unique across the whole database.

Examples

addUniqueConstraint('first_name_last_name_unique', ['first_name', 'last_name'])

In dialects such as PostgreSQL you can specify nulls not distinct as follows:

addUniqueConstraint('first_name_last_name_unique', ['first_name', 'last_name'], (builder) => builder.nullsNotDistinct())