fixes: #7156 - Adds support for PostgreSQL MultiRange type

This adds functionality for PostgreSQL MultiRange type, as discussed in Issue #7156.

As far as I can tell, only psycopg provides a [Multirange adaptation](https://www.psycopg.org/psycopg3/docs/basic/pgtypes.html#multirange-adaptation). Psycopg2 only supports a [Range adaptation/data type](https://www.psycopg.org/psycopg3/docs/basic/pgtypes.html#multirange-adaptation).

This pull request is:

- [ ] A documentation / typographical error fix
	- Good to go, no issue or tests are needed
- [ ] A short code fix
	- please include the issue number, and create an issue if none exists, which
	  must include a complete example of the issue.  one line code fixes without an
	  issue and demonstration will not be accepted.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.   one line code fixes without tests will not be accepted.
- [x] A new feature implementation
	- please include the issue number, and create an issue if none exists, which must
	  include a complete example of how the feature would look.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.

Closes: #7816
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/7816
Pull-request-sha: 7e9e0c858dcdb58d4fcca24964ef8d58d1842d41

Change-Id: I345e0f58f534ac37709a7a4627b6de8ddd8fa89e

3 files changed, 72 insertions, 0 deletions

diff --git a/lib/sqlalchemy/dialects/postgresql/__init__.py b/lib/sqlalchemy/dialects/postgresql/__init__.py
index 62195f59e..baafdb181 100644
--- a/lib/sqlalchemy/dialects/postgresql/__init__.py
+++ b/lib/sqlalchemy/dialects/postgresql/__init__.py
@@ -47,11 +47,17 @@ from .named_types import DropDomainType
 from .named_types import DropEnumType
 from .named_types import ENUM
 from .named_types import NamedType
+from .ranges import DATEMULTIRANGE
 from .ranges import DATERANGE
+from .ranges import INT4MULTIRANGE
 from .ranges import INT4RANGE
+from .ranges import INT8MULTIRANGE
 from .ranges import INT8RANGE
+from .ranges import NUMMULTIRANGE
 from .ranges import NUMRANGE
+from .ranges import TSMULTIRANGE
 from .ranges import TSRANGE
+from .ranges import TSTZMULTIRANGE
 from .ranges import TSTZRANGE
 from .types import BIT
 from .types import BYTEA
@@ -110,9 +116,15 @@ __all__ = (
     "INT8RANGE",
     "NUMRANGE",
     "DATERANGE",
+    "INT4MULTIRANGE",
+    "INT8MULTIRANGE",
+    "NUMMULTIRANGE",
+    "DATEMULTIRANGE",
     "TSVECTOR",
     "TSRANGE",
     "TSTZRANGE",
+    "TSMULTIRANGE",
+    "TSTZMULTIRANGE",
     "JSON",
     "JSONB",
     "Any",
diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index 8b89cdee2..efb4dd547 100644
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -1656,6 +1656,12 @@ ischema_names = {
     "daterange": _ranges.DATERANGE,
     "tsrange": _ranges.TSRANGE,
     "tstzrange": _ranges.TSTZRANGE,
+    "int4multirange": _ranges.INT4MULTIRANGE,
+    "int8multirange": _ranges.INT8MULTIRANGE,
+    "nummultirange": _ranges.NUMMULTIRANGE,
+    "datemultirange": _ranges.DATEMULTIRANGE,
+    "tsmultirange": _ranges.TSMULTIRANGE,
+    "tstzmultirange": _ranges.TSTZMULTIRANGE,
     "integer": INTEGER,
     "bigint": BIGINT,
     "smallint": SMALLINT,
@@ -2500,6 +2506,24 @@ class PGTypeCompiler(compiler.GenericTypeCompiler):
     def visit_JSONB(self, type_, **kw):
         return "JSONB"
 
+    def visit_INT4MULTIRANGE(self, type_, **kw):
+        return "INT4MULTIRANGE"
+
+    def visit_INT8MULTIRANGE(self, type_, **kw):
+        return "INT8MULTIRANGE"
+
+    def visit_NUMMULTIRANGE(self, type_, **kw):
+        return "NUMMULTIRANGE"
+
+    def visit_DATEMULTIRANGE(self, type_, **kw):
+        return "DATEMULTIRANGE"
+
+    def visit_TSMULTIRANGE(self, type_, **kw):
+        return "TSMULTIRANGE"
+
+    def visit_TSTZMULTIRANGE(self, type_, **kw):
+        return "TSTZMULTIRANGE"
+
     def visit_INT4RANGE(self, type_, **kw):
         return "INT4RANGE"
 
diff --git a/lib/sqlalchemy/dialects/postgresql/ranges.py b/lib/sqlalchemy/dialects/postgresql/ranges.py
index 81431ad59..4f010abf1 100644
--- a/lib/sqlalchemy/dialects/postgresql/ranges.py
+++ b/lib/sqlalchemy/dialects/postgresql/ranges.py
@@ -138,3 +138,39 @@ class TSTZRANGE(RangeOperators, sqltypes.TypeEngine):
     """Represent the PostgreSQL TSTZRANGE type."""
 
     __visit_name__ = "TSTZRANGE"
+
+
+class INT4MULTIRANGE(RangeOperators, sqltypes.TypeEngine):
+    """Represent the PostgreSQL INT4MULTIRANGE type."""
+
+    __visit_name__ = "INT4MULTIRANGE"
+
+
+class INT8MULTIRANGE(RangeOperators, sqltypes.TypeEngine):
+    """Represent the PostgreSQL INT8MULTIRANGE type."""
+
+    __visit_name__ = "INT8MULTIRANGE"
+
+
+class NUMMULTIRANGE(RangeOperators, sqltypes.TypeEngine):
+    """Represent the PostgreSQL NUMMULTIRANGE type."""
+
+    __visit_name__ = "NUMMULTIRANGE"
+
+
+class DATEMULTIRANGE(RangeOperators, sqltypes.TypeEngine):
+    """Represent the PostgreSQL DATEMULTIRANGE type."""
+
+    __visit_name__ = "DATEMULTIRANGE"
+
+
+class TSMULTIRANGE(RangeOperators, sqltypes.TypeEngine):
+    """Represent the PostgreSQL TSRANGE type."""
+
+    __visit_name__ = "TSMULTIRANGE"
+
+
+class TSTZMULTIRANGE(RangeOperators, sqltypes.TypeEngine):
+    """Represent the PostgreSQL TSTZRANGE type."""
+
+    __visit_name__ = "TSTZMULTIRANGE"