[Sqlalchemy-tickets] Issue #3161: Support partial unique constrains on PostgreSQL (zzzeek/sqlalchemy)

[Jonathan S. <iss...@bi...>]

New issue 3161: Support partial unique constrains on PostgreSQL
https://bitbucket.org/zzzeek/sqlalchemy/issue/3161/support-partial-unique-constrains-on

Jonathan Stoppani:

This is already supported for [normal indexes](http://docs.sqlalchemy.org/en/rel_0_9/dialects/postgresql.html?highlight=postgres#partial-indexes), but if I try to pass the `postgresql_where` keyword arg to `UniqueConstraint`, it fails with the following error:

    sqlalchemy.exc.ArgumentError: Argument 'postgresql_where' is not accepted by dialect 'postgresql' on behalf of <class 'sqlalchemy.sql.schema.UniqueConstraint'>