From 888f112b78e1cabc73eb410ecd8133df7b5cb957 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Wed, 30 Aug 2017 18:06:07 -0400 Subject: [PATCH] Enable native boolean for SQL Server SQL Server supports what SQLAlchemy calls "native boolean" with its BIT type, as this type only accepts 0 or 1 and the DBAPIs return its value as True/False. So the SQL Server dialects now enable "native boolean" support, in that a CHECK constraint is not generated for a :class:`.Boolean` datatype. The only difference vs. other native boolean is that there are no "true" / "false" constants so "1" and "0" are still rendered here. Tests are implicit in the existing suites. Change-Id: I75bbcd549884099fb1a177e68667bf880c40fa7c Fixes: #4061 --- doc/build/changelog/unreleased_12/4061.rst | 13 +++++++++++++ lib/sqlalchemy/dialects/mssql/base.py | 2 +- lib/sqlalchemy/sql/sqltypes.py | 12 ++++++------ 3 files changed, 20 insertions(+), 7 deletions(-) create mode 100644 doc/build/changelog/unreleased_12/4061.rst diff --git a/doc/build/changelog/unreleased_12/4061.rst b/doc/build/changelog/unreleased_12/4061.rst new file mode 100644 index 0000000000..63d6b9eb72 --- /dev/null +++ b/doc/build/changelog/unreleased_12/4061.rst @@ -0,0 +1,13 @@ +.. change:: + :tags: bug, mssql + :tickets: 4061 + + SQL Server supports what SQLAlchemy calls "native boolean" + with its BIT type, as this type only accepts 0 or 1 and the + DBAPIs return its value as True/False. So the SQL Server + dialects now enable "native boolean" support, in that a + CHECK constraint is not generated for a :class:`.Boolean` + datatype. The only difference vs. other native boolean + is that there are no "true" / "false" constants so "1" and + "0" are still rendered here. + diff --git a/lib/sqlalchemy/dialects/mssql/base.py b/lib/sqlalchemy/dialects/mssql/base.py index a4b9fe0ccb..84be8d0e3c 100644 --- a/lib/sqlalchemy/dialects/mssql/base.py +++ b/lib/sqlalchemy/dialects/mssql/base.py @@ -1730,7 +1730,7 @@ class MSDialect(default.DefaultDialect): ischema_names = ischema_names - supports_native_boolean = False + supports_native_boolean = True supports_unicode_binds = True postfetch_lastrowid = True diff --git a/lib/sqlalchemy/sql/sqltypes.py b/lib/sqlalchemy/sql/sqltypes.py index fe9a56b6ec..d0dbc48816 100644 --- a/lib/sqlalchemy/sql/sqltypes.py +++ b/lib/sqlalchemy/sql/sqltypes.py @@ -1603,12 +1603,12 @@ class Boolean(TypeEngine, SchemaType): return bool def literal_processor(self, dialect): - if dialect.supports_native_boolean: - def process(value): - return "true" if value else "false" - else: - def process(value): - return str(1 if value else 0) + compiler = dialect.statement_compiler(dialect, None) + true = compiler.visit_true(None) + false = compiler.visit_false(None) + + def process(value): + return true if value else false return process def bind_processor(self, dialect): -- 2.47.3