Support PostgreSQL DOMAINs

[janpio]

https://www.postgresql.org/docs/9.5/sql-createdomain.html

A domain is essentially a data type with optional constraints (restrictions on the allowed set of values).

Example:

CREATE DOMAIN year AS integer
	CONSTRAINT year_check CHECK (((VALUE >= 1901) AND (VALUE <= 2155)));

From: https://github.com/prisma/database-schema-examples/blob/master/postgres/sakila/schema.sql

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Test Utils database affected:

• postgres/sakila

[DamodarSojka]

Just hit that.

CREATE DOMAIN percent_max_100
    AS DOUBLE PRECISION
    CONSTRAINT max_100 CHECK ( value <= 100 )

Correctly mapped to Float by prisma during introspection.

However when issuing a query to set the value "incorrect binary data format in bind parameter X"

Would be good to at least have the documentation mention NOT to use domain. Or even better, the introspection warning about it, or not generate the mapping for the column. (Sorry if I missed it!)