From: Gord Thompson <gord@gordthompson.com>
Date: Thu, 22 Apr 2021 14:52:15 +0000 (-0600)
Subject: Add .as_generic() support to mssql BIT columns
X-Git-Tag: rel_1_4_12~11^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d23866e795a752ee4b4aaaa44addaf8b66547d6f;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

Add .as_generic() support to mssql BIT columns

Fixes: #6345
Change-Id: I2bdccc88e85c94d87519f58e474689ca7896f063
---

diff --git a/doc/build/changelog/unreleased_14/6345.rst b/doc/build/changelog/unreleased_14/6345.rst
new file mode 100644
index 0000000000..152e38c432
--- /dev/null
+++ b/doc/build/changelog/unreleased_14/6345.rst
@@ -0,0 +1,7 @@
+.. change::
+    :tags: bug, mssql, schema
+    :tickets: 6345
+
+    Add :meth:`_types.TypeEngine.as_generic` support for
+    :class:`sqlalchemy.dialects.mysql.BIT` columns, mapping
+    them to :class:`_sql.sqltypes.Boolean`.
diff --git a/lib/sqlalchemy/dialects/mssql/base.py b/lib/sqlalchemy/dialects/mssql/base.py
index 8c2abc8e7b..e59221f834 100644
--- a/lib/sqlalchemy/dialects/mssql/base.py
+++ b/lib/sqlalchemy/dialects/mssql/base.py
@@ -1255,7 +1255,14 @@ class XML(sqltypes.Text):
     __visit_name__ = "XML"
 
 
-class BIT(sqltypes.TypeEngine):
+class BIT(sqltypes.Boolean):
+    """MSSQL BIT type.
+
+    Both pyodbc and pymssql return values from BIT columns as
+    Python <class 'bool'> so just subclass Boolean.
+
+    """
+
     __visit_name__ = "BIT"
 
 
diff --git a/test/dialect/mssql/test_types.py b/test/dialect/mssql/test_types.py
index 4e78ec1220..798dbfc1fd 100644
--- a/test/dialect/mssql/test_types.py
+++ b/test/dialect/mssql/test_types.py
@@ -36,6 +36,7 @@ from sqlalchemy.dialects.mssql import base as mssql
 from sqlalchemy.dialects.mssql import ROWVERSION
 from sqlalchemy.dialects.mssql import TIMESTAMP
 from sqlalchemy.dialects.mssql.base import _MSDate
+from sqlalchemy.dialects.mssql.base import BIT
 from sqlalchemy.dialects.mssql.base import DATETIMEOFFSET
 from sqlalchemy.dialects.mssql.base import MS_2005_VERSION
 from sqlalchemy.dialects.mssql.base import MS_2008_VERSION
@@ -1342,3 +1343,31 @@ class BinaryTest(fixtures.TestBase):
         stream = fp.read(len_)
         fp.close()
         return stream
+
+
+class BooleanTest(fixtures.TestBase, AssertsCompiledSQL):
+    __only_on__ = "mssql"
+
+    @testing.provide_metadata
+    @testing.combinations(
+        ("as_boolean_null", Boolean, True, "CREATE TABLE tbl (boo BIT NULL)"),
+        ("as_bit_null", BIT, True, "CREATE TABLE tbl (boo BIT NULL)"),
+        (
+            "as_boolean_not_null",
+            Boolean,
+            False,
+            "CREATE TABLE tbl (boo BIT NOT NULL)",
+        ),
+        ("as_bit_not_null", BIT, False, "CREATE TABLE tbl (boo BIT NOT NULL)"),
+        id_="iaaa",
+        argnames="col_type, is_nullable, ddl",
+    )
+    def test_boolean_as_bit(self, col_type, is_nullable, ddl):
+        tbl = Table(
+            "tbl", self.metadata, Column("boo", col_type, nullable=is_nullable)
+        )
+        self.assert_compile(
+            schema.CreateTable(tbl),
+            ddl,
+        )
+        assert isinstance(tbl.c.boo.type.as_generic(), Boolean)