Merge pull request #15 from nicolasaldecoa/redshift-super-support

Add support for column types: PostgreSQL JSON/JSONB and RedShift Super

Author: Sergey Vasilyev

sqeleton/abcs/__init__.py

@@ -10,5 +10,6 @@
     PrecisionType,
     StringType,
     Boolean,
+    JSONType,
 )
 from .compiler import AbstractCompiler, Compilable

sqeleton/abcs/database_types.py

@@ -134,6 +134,22 @@ class Text(StringType):
     supported = False
 
 
+class JSONType(ColType):
+    pass
+
+
+class RedShiftSuper(JSONType):
+    pass
+
+
+class PostgresqlJSON(JSONType):
+    pass
+
+
+class PostgresqlJSONB(JSONType):
+    pass
+
+
 @dataclass
 class Integer(NumericType, IKey):
     precision: int = 0

sqeleton/abcs/mixins.py

@@ -1,5 +1,5 @@
 from abc import ABC, abstractmethod
-from .database_types import TemporalType, FractionalType, ColType_UUID, Boolean, ColType, String_UUID
+from .database_types import TemporalType, FractionalType, ColType_UUID, Boolean, ColType, String_UUID, JSONType
 from .compiler import Compilable
 
 
@@ -49,6 +49,10 @@ def normalize_uuid(self, value: str, coltype: ColType_UUID) -> str:
             return f"TRIM({value})"
         return self.to_string(value)
 
+    def normalize_json(self, value: str, _coltype: JSONType) -> str:
+        """Creates an SQL expression, that converts 'value' to its minified json string representation."""
+        raise NotImplementedError()
+
     def normalize_value_by_type(self, value: str, coltype: ColType) -> str:
         """Creates an SQL expression, that converts 'value' to a normalized representation.
 
@@ -73,6 +77,8 @@ def normalize_value_by_type(self, value: str, coltype: ColType) -> str:
             return self.normalize_uuid(value, coltype)
         elif isinstance(coltype, Boolean):
             return self.normalize_boolean(value, coltype)
+        elif isinstance(coltype, JSONType):
+            return self.normalize_json(value, coltype)
         return self.to_string(value)
 
 

sqeleton/databases/base.py

@@ -35,6 +35,7 @@
     DbTime,
     DbPath,
     Boolean,
+    JSONType
 )
 from ..abcs.mixins import Compilable
 from ..abcs.mixins import (
@@ -259,6 +260,9 @@ def parse_type(
         elif issubclass(cls, (Text, Native_UUID)):
             return cls()
 
+        elif issubclass(cls, JSONType):
+            return cls()
+
         raise TypeError(f"Parsing {type_repr} returned an unknown type '{cls}'.")
 
     def _convert_db_precision_to_digits(self, p: int) -> int:

sqeleton/databases/postgresql.py

@@ -11,6 +11,8 @@
     FractionalType,
     Boolean,
     Date,
+    PostgresqlJSON,
+    PostgresqlJSONB
 )
 from ..abcs.mixins import AbstractMixin_MD5, AbstractMixin_NormalizeValue
 from .base import BaseDialect, ThreadedDatabase, import_helper, ConnectError, Mixin_Schema
@@ -49,6 +51,9 @@ def normalize_number(self, value: str, coltype: FractionalType) -> str:
     def normalize_boolean(self, value: str, _coltype: Boolean) -> str:
         return self.to_string(f"{value}::int")
 
+    def normalize_json(self, value: str, _coltype: PostgresqlJSON) -> str:
+        return f"{value}::text"
+
 
 class PostgresqlDialect(BaseDialect, Mixin_Schema):
     name = "PostgreSQL"
@@ -76,6 +81,9 @@ class PostgresqlDialect(BaseDialect, Mixin_Schema):
         "character varying": Text,
         "varchar": Text,
         "text": Text,
+        # JSON
+        "json": PostgresqlJSON,
+        "jsonb": PostgresqlJSONB,
         # UUID
         "uuid": Native_UUID,
         # Boolean

sqeleton/databases/redshift.py

@@ -1,5 +1,12 @@
 from typing import List, Dict
-from ..abcs.database_types import Float, TemporalType, FractionalType, DbPath, TimestampTZ
+from ..abcs.database_types import (
+    Float,
+    TemporalType,
+    FractionalType,
+    DbPath,
+    TimestampTZ,
+    RedShiftSuper
+)
 from ..abcs.mixins import AbstractMixin_MD5
 from .postgresql import (
     PostgreSQL,
@@ -40,13 +47,18 @@ def normalize_timestamp(self, value: str, coltype: TemporalType) -> str:
     def normalize_number(self, value: str, coltype: FractionalType) -> str:
         return self.to_string(f"{value}::decimal(38,{coltype.precision})")
 
+    def normalize_json(self, value: str, _coltype: RedShiftSuper) -> str:
+        return f'nvl2({value}, json_serialize({value}), NULL)'
+
 
 class Dialect(PostgresqlDialect):
     name = "Redshift"
     TYPE_CLASSES = {
         **PostgresqlDialect.TYPE_CLASSES,
         "double": Float,
         "real": Float,
+        # JSON
+        "super": RedShiftSuper
     }
     SUPPORTS_INDEXES = False