JezK
Edit File: requirements.py
# testing/requirements.py # Copyright (C) 2005-2023 the SQLAlchemy authors and contributors # <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: https://www.opensource.org/licenses/mit-license.php """Global database feature support policy. Provides decorators to mark tests requiring specific feature support from the target database. External dialect test suites should subclass SuiteRequirements to provide specific inclusion/exclusions. """ import platform import sys from . import asyncio as _test_asyncio from . import exclusions from . import only_on from .. import util from ..pool import QueuePool class Requirements(object): pass class SuiteRequirements(Requirements): @property def create_table(self): """target platform can emit basic CreateTable DDL.""" return exclusions.open() @property def drop_table(self): """target platform can emit basic DropTable DDL.""" return exclusions.open() @property def table_ddl_if_exists(self): """target platform supports IF NOT EXISTS / IF EXISTS for tables.""" return exclusions.closed() @property def index_ddl_if_exists(self): """target platform supports IF NOT EXISTS / IF EXISTS for indexes.""" return exclusions.closed() @property def foreign_keys(self): """Target database must support foreign keys.""" return exclusions.open() @property def table_value_constructor(self): """Database / dialect supports a query like:: SELECT * FROM VALUES ( (c1, c2), (c1, c2), ...) AS some_table(col1, col2) SQLAlchemy generates this with the :func:`_sql.values` function. """ return exclusions.closed() @property def standard_cursor_sql(self): """Target database passes SQL-92 style statements to cursor.execute() when a statement like select() or insert() is run. A very small portion of dialect-level tests will ensure that certain conditions are present in SQL strings, and these tests use very basic SQL that will work on any SQL-like platform in order to assert results. It's normally a given for any pep-249 DBAPI that a statement like "SELECT id, name FROM table WHERE some_table.id=5" will work. However, there are dialects that don't actually produce SQL Strings and instead may work with symbolic objects instead, or dialects that aren't working with SQL, so for those this requirement can be marked as excluded. """ return exclusions.open() @property def on_update_cascade(self): """target database must support ON UPDATE..CASCADE behavior in foreign keys.""" return exclusions.open() @property def non_updating_cascade(self): """target database must *not* support ON UPDATE..CASCADE behavior in foreign keys.""" return exclusions.closed() @property def deferrable_fks(self): return exclusions.closed() @property def on_update_or_deferrable_fks(self): # TODO: exclusions should be composable, # somehow only_if([x, y]) isn't working here, negation/conjunctions # getting confused. return exclusions.only_if( lambda: self.on_update_cascade.enabled or self.deferrable_fks.enabled ) @property def queue_pool(self): """target database is using QueuePool""" def go(config): return isinstance(config.db.pool, QueuePool) return exclusions.only_if(go) @property def self_referential_foreign_keys(self): """Target database must support self-referential foreign keys.""" return exclusions.open() @property def foreign_key_ddl(self): """Target database must support the DDL phrases for FOREIGN KEY.""" return exclusions.open() @property def named_constraints(self): """target database must support names for constraints.""" return exclusions.open() @property def implicitly_named_constraints(self): """target database must apply names to unnamed constraints.""" return exclusions.open() @property def unusual_column_name_characters(self): """target database allows column names that have unusual characters in them, such as dots, spaces, slashes, or percent signs. The column names are as always in such a case quoted, however the DB still needs to support those characters in the name somehow. """ return exclusions.open() @property def subqueries(self): """Target database must support subqueries.""" return exclusions.open() @property def offset(self): """target database can render OFFSET, or an equivalent, in a SELECT. """ return exclusions.open() @property def bound_limit_offset(self): """target database can render LIMIT and/or OFFSET using a bound parameter """ return exclusions.open() @property def sql_expression_limit_offset(self): """target database can render LIMIT and/or OFFSET with a complete SQL expression, such as one that uses the addition operator. parameter """ return exclusions.open() @property def parens_in_union_contained_select_w_limit_offset(self): """Target database must support parenthesized SELECT in UNION when LIMIT/OFFSET is specifically present. E.g. (SELECT ...) UNION (SELECT ..) This is known to fail on SQLite. """ return exclusions.open() @property def parens_in_union_contained_select_wo_limit_offset(self): """Target database must support parenthesized SELECT in UNION when OFFSET/LIMIT is specifically not present. E.g. (SELECT ... LIMIT ..) UNION (SELECT .. OFFSET ..) This is known to fail on SQLite. It also fails on Oracle because without LIMIT/OFFSET, there is currently no step that creates an additional subquery. """ return exclusions.open() @property def boolean_col_expressions(self): """Target database must support boolean expressions as columns""" return exclusions.closed() @property def nullable_booleans(self): """Target database allows boolean columns to store NULL.""" return exclusions.open() @property def nullsordering(self): """Target backends that support nulls ordering.""" return exclusions.closed() @property def standalone_binds(self): """target database/driver supports bound parameters as column expressions without being in the context of a typed column. """ return exclusions.closed() @property def standalone_null_binds_whereclause(self): """target database/driver supports bound parameters with NULL in the WHERE clause, in situations where it has to be typed. """ return exclusions.open() @property def intersect(self): """Target database must support INTERSECT or equivalent.""" return exclusions.closed() @property def except_(self): """Target database must support EXCEPT or equivalent (i.e. MINUS).""" return exclusions.closed() @property def window_functions(self): """Target database must support window functions.""" return exclusions.closed() @property def ctes(self): """Target database supports CTEs""" return exclusions.closed() @property def ctes_with_update_delete(self): """target database supports CTES that ride on top of a normal UPDATE or DELETE statement which refers to the CTE in a correlated subquery. """ return exclusions.closed() @property def ctes_on_dml(self): """target database supports CTES which consist of INSERT, UPDATE or DELETE *within* the CTE, e.g. WITH x AS (UPDATE....)""" return exclusions.closed() @property def autoincrement_insert(self): """target platform generates new surrogate integer primary key values when insert() is executed, excluding the pk column.""" return exclusions.open() @property def fetch_rows_post_commit(self): """target platform will allow cursor.fetchone() to proceed after a COMMIT. Typically this refers to an INSERT statement with RETURNING which is invoked within "autocommit". If the row can be returned after the autocommit, then this rule can be open. """ return exclusions.open() @property def group_by_complex_expression(self): """target platform supports SQL expressions in GROUP BY e.g. SELECT x + y AS somelabel FROM table GROUP BY x + y """ return exclusions.open() @property def sane_rowcount(self): return exclusions.skip_if( lambda config: not config.db.dialect.supports_sane_rowcount, "driver doesn't support 'sane' rowcount", ) @property def sane_multi_rowcount(self): return exclusions.fails_if( lambda config: not config.db.dialect.supports_sane_multi_rowcount, "driver %(driver)s %(doesnt_support)s 'sane' multi row count", ) @property def sane_rowcount_w_returning(self): return exclusions.fails_if( lambda config: not ( config.db.dialect.supports_sane_rowcount_returning ), "driver doesn't support 'sane' rowcount when returning is on", ) @property def empty_inserts(self): """target platform supports INSERT with no values, i.e. INSERT DEFAULT VALUES or equivalent.""" return exclusions.only_if( lambda config: config.db.dialect.supports_empty_insert or config.db.dialect.supports_default_values or config.db.dialect.supports_default_metavalue, "empty inserts not supported", ) @property def empty_inserts_executemany(self): """target platform supports INSERT with no values, i.e. INSERT DEFAULT VALUES or equivalent, within executemany()""" return self.empty_inserts @property def insert_from_select(self): """target platform supports INSERT from a SELECT.""" return exclusions.open() @property def full_returning(self): """target platform supports RETURNING completely, including multiple rows returned. """ return exclusions.only_if( lambda config: config.db.dialect.full_returning, "%(database)s %(does_support)s 'RETURNING of multiple rows'", ) @property def insert_executemany_returning(self): """target platform supports RETURNING when INSERT is used with executemany(), e.g. multiple parameter sets, indicating as many rows come back as do parameter sets were passed. """ return exclusions.only_if( lambda config: config.db.dialect.insert_executemany_returning, "%(database)s %(does_support)s 'RETURNING of " "multiple rows with INSERT executemany'", ) @property def returning(self): """target platform supports RETURNING for at least one row. .. seealso:: :attr:`.Requirements.full_returning` """ return exclusions.only_if( lambda config: config.db.dialect.implicit_returning, "%(database)s %(does_support)s 'RETURNING of a single row'", ) @property def tuple_in(self): """Target platform supports the syntax "(x, y) IN ((x1, y1), (x2, y2), ...)" """ return exclusions.closed() @property def tuple_in_w_empty(self): """Target platform tuple IN w/ empty set""" return self.tuple_in @property def duplicate_names_in_cursor_description(self): """target platform supports a SELECT statement that has the same name repeated more than once in the columns list.""" return exclusions.open() @property def denormalized_names(self): """Target database must have 'denormalized', i.e. UPPERCASE as case insensitive names.""" return exclusions.skip_if( lambda config: not config.db.dialect.requires_name_normalize, "Backend does not require denormalized names.", ) @property def multivalues_inserts(self): """target database must support multiple VALUES clauses in an INSERT statement.""" return exclusions.skip_if( lambda config: not config.db.dialect.supports_multivalues_insert, "Backend does not support multirow inserts.", ) @property def implements_get_lastrowid(self): """target dialect implements the executioncontext.get_lastrowid() method without reliance on RETURNING. """ return exclusions.open() @property def emulated_lastrowid(self): """target dialect retrieves cursor.lastrowid, or fetches from a database-side function after an insert() construct executes, within the get_lastrowid() method. Only dialects that "pre-execute", or need RETURNING to get last inserted id, would return closed/fail/skip for this. """ return exclusions.closed() @property def emulated_lastrowid_even_with_sequences(self): """target dialect retrieves cursor.lastrowid or an equivalent after an insert() construct executes, even if the table has a Sequence on it. """ return exclusions.closed() @property def dbapi_lastrowid(self): """target platform includes a 'lastrowid' accessor on the DBAPI cursor object. """ return exclusions.closed() @property def views(self): """Target database must support VIEWs.""" return exclusions.closed() @property def schemas(self): """Target database must support external schemas, and have one named 'test_schema'.""" return only_on(lambda config: config.db.dialect.supports_schemas) @property def cross_schema_fk_reflection(self): """target system must support reflection of inter-schema foreign keys""" return exclusions.closed() @property def foreign_key_constraint_name_reflection(self): """Target supports refleciton of FOREIGN KEY constraints and will return the name of the constraint that was used in the "CONSTRAINT <name> FOREIGN KEY" DDL. MySQL prior to version 8 and MariaDB prior to version 10.5 don't support this. """ return exclusions.closed() @property def implicit_default_schema(self): """target system has a strong concept of 'default' schema that can be referred to implicitly. basically, PostgreSQL. """ return exclusions.closed() @property def default_schema_name_switch(self): """target dialect implements provisioning module including set_default_schema_on_connection""" return exclusions.closed() @property def server_side_cursors(self): """Target dialect must support server side cursors.""" return exclusions.only_if( [lambda config: config.db.dialect.supports_server_side_cursors], "no server side cursors support", ) @property def sequences(self): """Target database must support SEQUENCEs.""" return exclusions.only_if( [lambda config: config.db.dialect.supports_sequences], "no sequence support", ) @property def no_sequences(self): """the opposite of "sequences", DB does not support sequences at all.""" return exclusions.NotPredicate(self.sequences) @property def sequences_optional(self): """Target database supports sequences, but also optionally as a means of generating new PK values.""" return exclusions.only_if( [ lambda config: config.db.dialect.supports_sequences and config.db.dialect.sequences_optional ], "no sequence support, or sequences not optional", ) @property def supports_lastrowid(self): """target database / driver supports cursor.lastrowid as a means of retrieving the last inserted primary key value. note that if the target DB supports sequences also, this is still assumed to work. This is a new use case brought on by MariaDB 10.3. """ return exclusions.only_if( [lambda config: config.db.dialect.postfetch_lastrowid] ) @property def no_lastrowid_support(self): """the opposite of supports_lastrowid""" return exclusions.only_if( [lambda config: not config.db.dialect.postfetch_lastrowid] ) @property def reflects_pk_names(self): return exclusions.closed() @property def table_reflection(self): """target database has general support for table reflection""" return exclusions.open() @property def reflect_tables_no_columns(self): """target database supports creation and reflection of tables with no columns, or at least tables that seem to have no columns.""" return exclusions.closed() @property def comment_reflection(self): return exclusions.closed() @property def view_column_reflection(self): """target database must support retrieval of the columns in a view, similarly to how a table is inspected. This does not include the full CREATE VIEW definition. """ return self.views @property def view_reflection(self): """target database must support inspection of the full CREATE VIEW definition.""" return self.views @property def schema_reflection(self): return self.schemas @property def primary_key_constraint_reflection(self): return exclusions.open() @property def foreign_key_constraint_reflection(self): return exclusions.open() @property def foreign_key_constraint_option_reflection_ondelete(self): return exclusions.closed() @property def fk_constraint_option_reflection_ondelete_restrict(self): return exclusions.closed() @property def fk_constraint_option_reflection_ondelete_noaction(self): return exclusions.closed() @property def foreign_key_constraint_option_reflection_onupdate(self): return exclusions.closed() @property def fk_constraint_option_reflection_onupdate_restrict(self): return exclusions.closed() @property def temp_table_reflection(self): return exclusions.open() @property def temp_table_reflect_indexes(self): return self.temp_table_reflection @property def temp_table_names(self): """target dialect supports listing of temporary table names""" return exclusions.closed() @property def has_temp_table(self): """target dialect supports checking a single temp table name""" return exclusions.closed() @property def temporary_tables(self): """target database supports temporary tables""" return exclusions.open() @property def temporary_views(self): """target database supports temporary views""" return exclusions.closed() @property def index_reflection(self): return exclusions.open() @property def index_reflects_included_columns(self): return exclusions.closed() @property def indexes_with_ascdesc(self): """target database supports CREATE INDEX with per-column ASC/DESC.""" return exclusions.open() @property def indexes_with_expressions(self): """target database supports CREATE INDEX against SQL expressions.""" return exclusions.closed() @property def unique_constraint_reflection(self): """target dialect supports reflection of unique constraints""" return exclusions.open() @property def check_constraint_reflection(self): """target dialect supports reflection of check constraints""" return exclusions.closed() @property def duplicate_key_raises_integrity_error(self): """target dialect raises IntegrityError when reporting an INSERT with a primary key violation. (hint: it should) """ return exclusions.open() @property def unbounded_varchar(self): """Target database must support VARCHAR with no length""" return exclusions.open() @property def unicode_data(self): """Target database/dialect must support Python unicode objects with non-ASCII characters represented, delivered as bound parameters as well as in result rows. """ return exclusions.open() @property def unicode_ddl(self): """Target driver must support some degree of non-ascii symbol names. """ return exclusions.closed() @property def symbol_names_w_double_quote(self): """Target driver can create tables with a name like 'some " table'""" return exclusions.open() @property def datetime_literals(self): """target dialect supports rendering of a date, time, or datetime as a literal string, e.g. via the TypeEngine.literal_processor() method. """ return exclusions.closed() @property def datetime(self): """target dialect supports representation of Python datetime.datetime() objects.""" return exclusions.open() @property def datetime_timezone(self): """target dialect supports representation of Python datetime.datetime() with tzinfo with DateTime(timezone=True).""" return exclusions.closed() @property def time_timezone(self): """target dialect supports representation of Python datetime.time() with tzinfo with Time(timezone=True).""" return exclusions.closed() @property def datetime_implicit_bound(self): """target dialect when given a datetime object will bind it such that the database server knows the object is a datetime, and not a plain string. """ return exclusions.open() @property def datetime_microseconds(self): """target dialect supports representation of Python datetime.datetime() with microsecond objects.""" return exclusions.open() @property def timestamp_microseconds(self): """target dialect supports representation of Python datetime.datetime() with microsecond objects but only if TIMESTAMP is used.""" return exclusions.closed() @property def timestamp_microseconds_implicit_bound(self): """target dialect when given a datetime object which also includes a microseconds portion when using the TIMESTAMP data type will bind it such that the database server knows the object is a datetime with microseconds, and not a plain string. """ return self.timestamp_microseconds @property def datetime_historic(self): """target dialect supports representation of Python datetime.datetime() objects with historic (pre 1970) values.""" return exclusions.closed() @property def date(self): """target dialect supports representation of Python datetime.date() objects.""" return exclusions.open() @property def date_coerces_from_datetime(self): """target dialect accepts a datetime object as the target of a date column.""" return exclusions.open() @property def date_historic(self): """target dialect supports representation of Python datetime.datetime() objects with historic (pre 1970) values.""" return exclusions.closed() @property def time(self): """target dialect supports representation of Python datetime.time() objects.""" return exclusions.open() @property def time_microseconds(self): """target dialect supports representation of Python datetime.time() with microsecond objects.""" return exclusions.open() @property def binary_comparisons(self): """target database/driver can allow BLOB/BINARY fields to be compared against a bound parameter value. """ return exclusions.open() @property def binary_literals(self): """target backend supports simple binary literals, e.g. an expression like:: SELECT CAST('foo' AS BINARY) Where ``BINARY`` is the type emitted from :class:`.LargeBinary`, e.g. it could be ``BLOB`` or similar. Basically fails on Oracle. """ return exclusions.open() @property def autocommit(self): """target dialect supports 'AUTOCOMMIT' as an isolation_level""" return exclusions.closed() @property def isolation_level(self): """target dialect supports general isolation level settings. Note that this requirement, when enabled, also requires that the get_isolation_levels() method be implemented. """ return exclusions.closed() def get_isolation_levels(self, config): """Return a structure of supported isolation levels for the current testing dialect. The structure indicates to the testing suite what the expected "default" isolation should be, as well as the other values that are accepted. The dictionary has two keys, "default" and "supported". The "supported" key refers to a list of all supported levels and it should include AUTOCOMMIT if the dialect supports it. If the :meth:`.DefaultRequirements.isolation_level` requirement is not open, then this method has no return value. E.g.:: >>> testing.requirements.get_isolation_levels() { "default": "READ_COMMITTED", "supported": [ "SERIALIZABLE", "READ UNCOMMITTED", "READ COMMITTED", "REPEATABLE READ", "AUTOCOMMIT" ] } """ @property def json_type(self): """target platform implements a native JSON type.""" return exclusions.closed() @property def json_array_indexes(self): """target platform supports numeric array indexes within a JSON structure""" return self.json_type @property def json_index_supplementary_unicode_element(self): return exclusions.open() @property def legacy_unconditional_json_extract(self): """Backend has a JSON_EXTRACT or similar function that returns a valid JSON string in all cases. Used to test a legacy feature and is not needed. """ return exclusions.closed() @property def precision_numerics_general(self): """target backend has general support for moderately high-precision numerics.""" return exclusions.open() @property def precision_numerics_enotation_small(self): """target backend supports Decimal() objects using E notation to represent very small values.""" return exclusions.closed() @property def precision_numerics_enotation_large(self): """target backend supports Decimal() objects using E notation to represent very large values.""" return exclusions.closed() @property def precision_numerics_many_significant_digits(self): """target backend supports values with many digits on both sides, such as 319438950232418390.273596, 87673.594069654243 """ return exclusions.closed() @property def cast_precision_numerics_many_significant_digits(self): """same as precision_numerics_many_significant_digits but within the context of a CAST statement (hello MySQL) """ return self.precision_numerics_many_significant_digits @property def implicit_decimal_binds(self): """target backend will return a selected Decimal as a Decimal, not a string. e.g.:: expr = decimal.Decimal("15.7563") value = e.scalar( select(literal(expr)) ) assert value == expr See :ticket:`4036` """ return exclusions.open() @property def nested_aggregates(self): """target database can select an aggregate from a subquery that's also using an aggregate """ return exclusions.open() @property def recursive_fk_cascade(self): """target database must support ON DELETE CASCADE on a self-referential foreign key """ return exclusions.open() @property def precision_numerics_retains_significant_digits(self): """A precision numeric type will return empty significant digits, i.e. a value such as 10.000 will come back in Decimal form with the .000 maintained.""" return exclusions.closed() @property def infinity_floats(self): """The Float type can persist and load float('inf'), float('-inf').""" return exclusions.closed() @property def precision_generic_float_type(self): """target backend will return native floating point numbers with at least seven decimal places when using the generic Float type. """ return exclusions.open() @property def floats_to_four_decimals(self): """target backend can return a floating-point number with four significant digits (such as 15.7563) accurately (i.e. without FP inaccuracies, such as 15.75629997253418). """ return exclusions.open() @property def fetch_null_from_numeric(self): """target backend doesn't crash when you try to select a NUMERIC value that has a value of NULL. Added to support Pyodbc bug #351. """ return exclusions.open() @property def text_type(self): """Target database must support an unbounded Text() " "type such as TEXT or CLOB""" return exclusions.open() @property def empty_strings_varchar(self): """target database can persist/return an empty string with a varchar. """ return exclusions.open() @property def empty_strings_text(self): """target database can persist/return an empty string with an unbounded text.""" return exclusions.open() @property def expressions_against_unbounded_text(self): """target database supports use of an unbounded textual field in a WHERE clause.""" return exclusions.open() @property def selectone(self): """target driver must support the literal statement 'select 1'""" return exclusions.open() @property def savepoints(self): """Target database must support savepoints.""" return exclusions.closed() @property def two_phase_transactions(self): """Target database must support two-phase transactions.""" return exclusions.closed() @property def update_from(self): """Target must support UPDATE..FROM syntax""" return exclusions.closed() @property def delete_from(self): """Target must support DELETE FROM..FROM or DELETE..USING syntax""" return exclusions.closed() @property def update_where_target_in_subquery(self): """Target must support UPDATE (or DELETE) where the same table is present in a subquery in the WHERE clause. This is an ANSI-standard syntax that apparently MySQL can't handle, such as:: UPDATE documents SET flag=1 WHERE documents.title IN (SELECT max(documents.title) AS title FROM documents GROUP BY documents.user_id ) """ return exclusions.open() @property def mod_operator_as_percent_sign(self): """target database must use a plain percent '%' as the 'modulus' operator.""" return exclusions.closed() @property def percent_schema_names(self): """target backend supports weird identifiers with percent signs in them, e.g. 'some % column'. this is a very weird use case but often has problems because of DBAPIs that use python formatting. It's not a critical use case either. """ return exclusions.closed() @property def order_by_col_from_union(self): """target database supports ordering by a column from a SELECT inside of a UNION E.g. (SELECT id, ...) UNION (SELECT id, ...) ORDER BY id """ return exclusions.open() @property def order_by_label_with_expression(self): """target backend supports ORDER BY a column label within an expression. Basically this:: select data as foo from test order by foo || 'bar' Lots of databases including PostgreSQL don't support this, so this is off by default. """ return exclusions.closed() @property def order_by_collation(self): def check(config): try: self.get_order_by_collation(config) return False except NotImplementedError: return True return exclusions.skip_if(check) def get_order_by_collation(self, config): raise NotImplementedError() @property def unicode_connections(self): """Target driver must support non-ASCII characters being passed at all. """ return exclusions.open() @property def graceful_disconnects(self): """Target driver must raise a DBAPI-level exception, such as InterfaceError, when the underlying connection has been closed and the execute() method is called. """ return exclusions.open() @property def independent_connections(self): """ Target must support simultaneous, independent database connections. """ return exclusions.open() @property def skip_mysql_on_windows(self): """Catchall for a large variety of MySQL on Windows failures""" return exclusions.open() @property def ad_hoc_engines(self): """Test environment must allow ad-hoc engine/connection creation. DBs that scale poorly for many connections, even when closed, i.e. Oracle, may use the "--low-connections" option which flags this requirement as not present. """ return exclusions.skip_if( lambda config: config.options.low_connections ) @property def no_windows(self): return exclusions.skip_if(self._running_on_windows()) def _running_on_windows(self): return exclusions.LambdaPredicate( lambda: platform.system() == "Windows", description="running on Windows", ) @property def timing_intensive(self): return exclusions.requires_tag("timing_intensive") @property def memory_intensive(self): return exclusions.requires_tag("memory_intensive") @property def threading_with_mock(self): """Mark tests that use threading and mock at the same time - stability issues have been observed with coverage + python 3.3 """ return exclusions.skip_if( lambda config: util.py3k and config.options.has_coverage, "Stability issues with coverage + py3k", ) @property def sqlalchemy2_stubs(self): def check(config): try: __import__("sqlalchemy-stubs.ext.mypy") except ImportError: return False else: return True return exclusions.only_if(check) @property def python2(self): return exclusions.skip_if( lambda: sys.version_info >= (3,), "Python version 2.xx is required.", ) @property def python3(self): return exclusions.skip_if( lambda: sys.version_info < (3,), "Python version 3.xx is required." ) @property def pep520(self): return self.python36 @property def insert_order_dicts(self): return self.python37 @property def python36(self): return exclusions.skip_if( lambda: sys.version_info < (3, 6), "Python version 3.6 or greater is required.", ) @property def python37(self): return exclusions.skip_if( lambda: sys.version_info < (3, 7), "Python version 3.7 or greater is required.", ) @property def dataclasses(self): return self.python37 @property def python38(self): return exclusions.only_if( lambda: util.py38, "Python 3.8 or above required" ) @property def cpython(self): return exclusions.only_if( lambda: util.cpython, "cPython interpreter needed" ) @property def is64bit(self): return exclusions.only_if(lambda: util.is64bit, "64bit required") @property def patch_library(self): def check_lib(): try: __import__("patch") except ImportError: return False else: return True return exclusions.only_if(check_lib, "patch library needed") @property def non_broken_pickle(self): from sqlalchemy.util import pickle return exclusions.only_if( lambda: util.cpython and pickle.__name__ == "cPickle" or sys.version_info >= (3, 2), "Needs cPickle+cPython or newer Python 3 pickle", ) @property def predictable_gc(self): """target platform must remove all cycles unconditionally when gc.collect() is called, as well as clean out unreferenced subclasses. """ return self.cpython @property def no_coverage(self): """Test should be skipped if coverage is enabled. This is to block tests that exercise libraries that seem to be sensitive to coverage, such as PostgreSQL notice logging. """ return exclusions.skip_if( lambda config: config.options.has_coverage, "Issues observed when coverage is enabled", ) def _has_mysql_on_windows(self, config): return False def _has_mysql_fully_case_sensitive(self, config): return False @property def sqlite(self): return exclusions.skip_if(lambda: not self._has_sqlite()) @property def cextensions(self): return exclusions.skip_if( lambda: not util.has_compiled_ext(), "C extensions not installed" ) def _has_sqlite(self): from sqlalchemy import create_engine try: create_engine("sqlite://") return True except ImportError: return False @property def async_dialect(self): """dialect makes use of await_() to invoke operations on the DBAPI.""" return exclusions.closed() @property def asyncio(self): return self.greenlet @property def greenlet(self): def go(config): if not _test_asyncio.ENABLE_ASYNCIO: return False try: import greenlet # noqa: F401 except ImportError: return False else: return True return exclusions.only_if(go) @property def computed_columns(self): "Supports computed columns" return exclusions.closed() @property def computed_columns_stored(self): "Supports computed columns with `persisted=True`" return exclusions.closed() @property def computed_columns_virtual(self): "Supports computed columns with `persisted=False`" return exclusions.closed() @property def computed_columns_default_persisted(self): """If the default persistence is virtual or stored when `persisted` is omitted""" return exclusions.closed() @property def computed_columns_reflect_persisted(self): """If persistence information is returned by the reflection of computed columns""" return exclusions.closed() @property def supports_distinct_on(self): """If a backend supports the DISTINCT ON in a select""" return exclusions.closed() @property def supports_is_distinct_from(self): """Supports some form of "x IS [NOT] DISTINCT FROM y" construct. Different dialects will implement their own flavour, e.g., sqlite will emit "x IS NOT y" instead of "x IS DISTINCT FROM y". .. seealso:: :meth:`.ColumnOperators.is_distinct_from` """ return exclusions.skip_if( lambda config: not config.db.dialect.supports_is_distinct_from, "driver doesn't support an IS DISTINCT FROM construct", ) @property def identity_columns(self): """If a backend supports GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY""" return exclusions.closed() @property def identity_columns_standard(self): """If a backend supports GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY with a standard syntax. This is mainly to exclude MSSql. """ return exclusions.closed() @property def regexp_match(self): """backend supports the regexp_match operator.""" return exclusions.closed() @property def regexp_replace(self): """backend supports the regexp_replace operator.""" return exclusions.closed() @property def fetch_first(self): """backend supports the fetch first clause.""" return exclusions.closed() @property def fetch_percent(self): """backend supports the fetch first clause with percent.""" return exclusions.closed() @property def fetch_ties(self): """backend supports the fetch first clause with ties.""" return exclusions.closed() @property def fetch_no_order_by(self): """backend supports the fetch first without order by""" return exclusions.closed() @property def fetch_offset_with_options(self): """backend supports the offset when using fetch first with percent or ties. basically this is "not mssql" """ return exclusions.closed() @property def fetch_expression(self): """backend supports fetch / offset with expression in them, like SELECT * FROM some_table OFFSET 1 + 1 ROWS FETCH FIRST 1 + 1 ROWS ONLY """ return exclusions.closed() @property def autoincrement_without_sequence(self): """If autoincrement=True on a column does not require an explicit sequence. This should be false only for oracle. """ return exclusions.open() @property def generic_classes(self): "If X[Y] can be implemented with ``__class_getitem__``. py3.7+" return exclusions.only_if(lambda: util.py37)