- add a postgresql-specific form of array_agg() that injects the

ARRAY type, references #3132

4 files changed, 24 insertions, 4 deletions

diff --git a/lib/sqlalchemy/dialects/postgresql/__init__.py b/lib/sqlalchemy/dialects/postgresql/__init__.py
index 2dac6cecc..d67f2a07e 100644
--- a/lib/sqlalchemy/dialects/postgresql/__init__.py
+++ b/lib/sqlalchemy/dialects/postgresql/__init__.py
@@ -17,7 +17,7 @@ from .base import \
 from .hstore import HSTORE, hstore
 from .json import JSON, JSONB
 from .array import array, ARRAY, Any, All
-from .ext import aggregate_order_by, ExcludeConstraint
+from .ext import aggregate_order_by, ExcludeConstraint, array_agg
 
 from .ranges import INT4RANGE, INT8RANGE, NUMRANGE, DATERANGE, TSRANGE, \
     TSTZRANGE
@@ -29,5 +29,6 @@ __all__ = (
     'INTERVAL', 'ARRAY', 'ENUM', 'dialect', 'array', 'HSTORE',
     'hstore', 'INT4RANGE', 'INT8RANGE', 'NUMRANGE', 'DATERANGE',
     'TSRANGE', 'TSTZRANGE', 'json', 'JSON', 'JSONB', 'Any', 'All',
-    'DropEnumType', 'CreateEnumType', 'ExcludeConstraint', 'aggregate_order_by'
+    'DropEnumType', 'CreateEnumType', 'ExcludeConstraint',
+    'aggregate_order_by', 'array_agg'
 )
diff --git a/lib/sqlalchemy/dialects/postgresql/array.py b/lib/sqlalchemy/dialects/postgresql/array.py
index 68c7b0bdb..ebdfe1695 100644
--- a/lib/sqlalchemy/dialects/postgresql/array.py
+++ b/lib/sqlalchemy/dialects/postgresql/array.py
@@ -22,7 +22,7 @@ def Any(other, arrexpr, operator=operators.eq):
 
     .. seealso::
 
-        :func:`.expression.any`
+        :func:`.expression.any_`
 
     """
 
@@ -36,7 +36,7 @@ def All(other, arrexpr, operator=operators.eq):
 
     .. seealso::
 
-        :func:`.expression.all`
+        :func:`.expression.all_`
 
     """
 
diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index 4022db14b..ec12e1145 100644
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -518,6 +518,11 @@ as well as array literals:
 
 * :class:`.postgresql.array` - array literal
 
+* :func:`.postgresql.array_agg` - ARRAY_AGG SQL function
+
+* :class:`.postgresql.aggregate_order_by` - helper for PG's ORDER BY aggregate
+  function syntax.
+
 JSON Types
 ----------
 
diff --git a/lib/sqlalchemy/dialects/postgresql/ext.py b/lib/sqlalchemy/dialects/postgresql/ext.py
index 8b08cc498..9b2e3fd73 100644
--- a/lib/sqlalchemy/dialects/postgresql/ext.py
+++ b/lib/sqlalchemy/dialects/postgresql/ext.py
@@ -7,7 +7,9 @@
 
 from ...sql import expression
 from ...sql import elements
+from ...sql import functions
 from ...sql.schema import ColumnCollectionConstraint
+from .array import ARRAY
 
 
 class aggregate_order_by(expression.ColumnElement):
@@ -152,3 +154,15 @@ static/sql-createtable.html#SQL-CREATETABLE-EXCLUDE
                            initially=self.initially)
         c.dispatch._update(self.dispatch)
         return c
+
+
+def array_agg(*arg, **kw):
+    """Postgresql-specific form of :class:`.array_agg`, ensures
+    return type is :class:`.postgresql.ARRAY` and not
+    the plain :class:`.types.Array`.
+
+    .. versionadded:: 1.1
+
+    """
+    kw['type_'] = ARRAY(functions._type_from_args(arg))
+    return functions.func.array_agg(*arg, **kw)