sqlalchemy.dialects.mssql.base.MSDialect

class documentation

class MSDialect(default.DefaultDialect): (source)

Known subclasses: sqlalchemy.dialects.mssql.pymssql.MSDialect_pymssql, sqlalchemy.dialects.mssql.pyodbc.MSDialect_pyodbc

View In Hierarchy

Undocumented

Method __init__ Undocumented
Method do_release_savepoint Release the named savepoint on a connection.
Method do_rollback Provide an implementation of ``connection.rollback()``, given a DB-API connection.
Method do_savepoint Create a savepoint with the given name.
Method get_columns Return information about columns in ``table_name``.
Method get_foreign_keys Return information about foreign_keys in ``table_name``.
Method get_indexes Return information about indexes in ``table_name``.
Method get_isolation_level Given a DBAPI connection, return its isolation level.
Method get_isolation_level_values return a sequence of string isolation level names that are accepted by this dialect.
Method get_pk_constraint Return information about the primary key constraint on table_name`.
Method get_schema_names Return a list of all schema names available in the database.
Method get_sequence_names Return a list of all sequence names available in the database.
Method get_table_comment Return the "comment" for the table identified by ``table_name``.
Method get_table_names Return a list of table names for ``schema``.
Method get_view_definition Return plain or materialized view definition.
Method get_view_names Return a list of all non-materialized view names available in the database.
Method has_sequence Check the existence of a particular sequence in the database.
Method has_table For internal dialect use, check the existence of a particular table or view in the database.
Method initialize Called during strategized creation of the dialect with a connection.
Method set_isolation_level Given a DBAPI connection, set its isolation level.
Class Variable colspecs A dictionary of TypeEngine classes from sqlalchemy.types mapped to subclasses that are specific to the dialect class. This dictionary is class-level only and is not accessed from the dialect instance itself.
Class Variable construct_arguments Optional set of argument specifiers for various SQLAlchemy constructs, typically schema items.
Class Variable default_sequence_base the default value that will be rendered as the "START WITH" portion of a CREATE SEQUENCE DDL statement.
Class Variable delete_returning if the dialect supports RETURNING with DELETE
Class Variable delete_returning_multifrom if the dialect supports RETURNING with DELETE..FROM
Class Variable engine_config_types a mapping of string keys that can be in an engine config linked to type conversion functions.
Class Variable favor_returning_over_lastrowid for backends that support both a lastrowid and a RETURNING insert strategy, favor RETURNING for simple single-int pk inserts.
Class Variable insert_returning if the dialect supports RETURNING with INSERT
Class Variable insertmanyvalues_max_parameters Alternate to insertmanyvalues_page_size, will additionally limit page size based on number of parameters total in the statement.
Class Variable max_identifier_length The maximum length of identifier names.
Class Variable name identifying name for the dialect from a DBAPI-neutral point of view (i.e. 'sqlite')
Class Variable non_native_boolean_check_constraint Undocumented
Class Variable postfetch_lastrowid Undocumented
Class Variable sequences_optional If True, indicates if the :paramref:`_schema.Sequence.optional` parameter on the :class:`_schema.Sequence` construct should signal to not generate a CREATE SEQUENCE. Applies only to dialects that support sequences...
Class Variable server_version_info a tuple containing a version number for the DB backend in use.
Class Variable supports_default_metavalue dialect supports INSERT... VALUES (DEFAULT) syntax - SQL Server **does** support this, but **not** for the IDENTITY column, so we can't turn this on.
Class Variable supports_default_values dialect supports INSERT... DEFAULT VALUES syntax
Class Variable supports_empty_insert dialect supports INSERT () VALUES ()
Class Variable supports_native_boolean Indicates if the dialect supports a native boolean construct. This will prevent :class:`_types.Boolean` from generating a CHECK constraint when that type is used.
Class Variable supports_sequences Indicates if the dialect supports CREATE SEQUENCE or similar.
Class Variable supports_statement_cache indicates if this dialect supports caching.
Class Variable supports_unicode_binds Undocumented
Class Variable update_returning if the dialect supports RETURNING with UPDATE
Class Variable update_returning_multifrom if the dialect supports RETURNING with UPDATE..FROM
Class Variable use_insertmanyvalues if True, indicates "insertmanyvalues" functionality should be used to allow for ``insert_executemany_returning`` behavior, if possible.
Class Variable use_insertmanyvalues_wo_returning if True, and use_insertmanyvalues is also True, INSERT statements that don't include RETURNING will also use "insertmanyvalues".
Instance Variable deprecate_large_types Undocumented
Instance Variable ignore_no_transaction_on_rollback Undocumented
Instance Variable legacy_schema_aliasing Undocumented
Instance Variable query_timeout Undocumented
Instance Variable schema_name Undocumented
Instance Variable supports_comments Indicates the dialect supports comment DDL on tables and columns.
Instance Variable supports_multivalues_insert Target database supports INSERT...VALUES with multiple value sets, i.e. INSERT INTO table (cols) VALUES (...), (...), (...), ...
Instance Variable use_scope_identity Undocumented
Method _default_or_error Undocumented
Method _get_default_schema_name Return the string name of the currently selected schema from the given connection.
Method _get_internal_temp_table_name Undocumented
Method _internal_has_table Undocumented
Method _setup_supports_comments Undocumented
Method _setup_supports_nvarchar_max Undocumented
Method _setup_version_attributes Undocumented
Method _temp_table_name_like_pattern Undocumented
Class Variable _isolation_lookup Undocumented
Class Variable _supports_nvarchar_max Undocumented
Instance Variable _json_deserializer Undocumented
Instance Variable _json_serializer Undocumented
Instance Variable _supports_offset_fetch Undocumented
Instance Variable _user_defined_supports_comments Undocumented

Inherited from DefaultDialect:

Class Method get_pool_class Undocumented
Class Method load_provisioning set up the provision.py module for this dialect.
Method connect Establish a connection using this dialect's DBAPI.
Method create_connect_args Build DB-API compatible connection arguments.
Method create_xid Create a random two-phase transaction ID.
Method denormalize_name convert the given name to a case insensitive identifier for the backend if it is an all-lowercase name.
Method do_begin Provide an implementation of ``connection.begin()``, given a DB-API connection.
Method do_close Provide an implementation of ``connection.close()``, given a DBAPI connection.
Method do_commit Provide an implementation of ``connection.commit()``, given a DB-API connection.
Method do_execute Provide an implementation of ``cursor.execute(statement, parameters)``.
Method do_execute_no_params Provide an implementation of ``cursor.execute(statement)``.
Method do_executemany Provide an implementation of ``cursor.executemany(statement, parameters)``.
Method do_ping ping the DBAPI connection and return True if the connection is usable.
Method do_rollback_to_savepoint Rollback a connection to the named savepoint.
Method do_terminate Provide an implementation of ``connection.close()`` that tries as much as possible to not block, given a DBAPI connection.
Method get_default_isolation_level Given a DBAPI connection, return its isolation level, or a default isolation level if one cannot be retrieved.
Method get_dialect_pool_class return a Pool class to use for a given URL
Method get_driver_connection Returns the connection object as returned by the external driver package.
Method get_multi_check_constraints Return information about check constraints in all tables in the given ``schema``.
Method get_multi_columns Return information about columns in all tables in the given ``schema``.
Method get_multi_foreign_keys Return information about foreign_keys in all tables in the given ``schema``.
Method get_multi_indexes Return information about indexes in in all tables in the given ``schema``.
Method get_multi_pk_constraint Return information about primary key constraints in all tables in the given ``schema``.
Method get_multi_table_comment Return information about the table comment in all tables in the given ``schema``.
Method get_multi_table_options Return a dictionary of options specified when the tables in the given schema were created.
Method get_multi_unique_constraints Return information about unique constraints in all tables in the given ``schema``.
Method has_index Check the existence of a particular index name in the database.
Method has_schema Check the existence of a particular schema name in the database.
Method is_disconnect Return True if the given DB-API error indicates an invalid connection
Method normalize_name convert the given name to lowercase if it is detected as case insensitive.
Method on_connect return a callable which sets up a newly created DBAPI connection.
Method reset_isolation_level Given a DBAPI connection, revert its isolation to the default.
Method set_connection_execution_options Establish execution options for a given connection.
Method set_engine_execution_options Establish execution options for a given engine.
Method type_descriptor Provide a database-specific :class:`.TypeEngine` object, given the generic object which comes from the types module.
Method validate_identifier Undocumented
Class Variable connection_characteristics Undocumented
Class Variable cte_follows_insert target database, when given a CTE with an INSERT statement, needs the CTE to be below the INSERT
Class Variable default_metavalue_token for INSERT... VALUES (DEFAULT) syntax, the token to put in the parenthesis.
Class Variable default_paramstyle Undocumented
Class Variable delete_executemany_returning dialect supports DELETE..RETURNING with executemany.
Class Variable div_is_floordiv target database treats the / division operator as "floor division"
Class Variable exclude_set_input_sizes set of DBAPI type objects that should be excluded in automatic cursor.setinputsizes() calls.
Class Variable has_terminate Whether or not this dialect has a separate "terminate" implementation that does not block or require awaiting.
Class Variable include_set_input_sizes set of DBAPI type objects that should be included in automatic cursor.setinputsizes() calls.
Class Variable inline_comments Indicates the dialect supports comment DDL that's inline with the definition of a Table or Column. If False, this implies that ALTER must be used to set table and column comments.
Class Variable insert_null_pk_still_autoincrements Undocumented
Class Variable is_async Whether or not this dialect is intended for asyncio use.
Class Variable isolation_level Undocumented
Class Variable max_constraint_name_length Undocumented
Class Variable max_index_name_length Undocumented
Class Variable preexecute_autoincrement_sequences True if 'implicit' primary key functions must be executed separately in order to get their value, if RETURNING is not used.
Class Variable requires_name_normalize Undocumented
Class Variable server_side_cursors deprecated; indicates if the dialect should attempt to use server side cursors by default
Class Variable supports_alter ``True`` if the database supports ``ALTER TABLE`` - used only for generating foreign key constraints in certain circumstances
Class Variable supports_constraint_comments Indicates if the dialect supports comment DDL on constraints.
Class Variable supports_for_update_of Undocumented
Class Variable supports_identity_columns target database supports IDENTITY
Class Variable supports_is_distinct_from Undocumented
Class Variable supports_native_decimal indicates if Decimal objects are handled and returned for precision numeric types, or if floats are returned
Class Variable supports_native_enum Indicates if the dialect supports a native ENUM construct. This will prevent :class:`_types.Enum` from generating a CHECK constraint when that type is used in "native" mode.
Class Variable supports_native_uuid indicates if Python UUID() objects are handled natively by the driver for SQL UUID datatypes.
Class Variable supports_sane_multi_rowcount Indicate whether the dialect properly implements rowcount for ``UPDATE`` and ``DELETE`` statements when executed via executemany.
Class Variable supports_sane_rowcount Indicate whether the dialect properly implements rowcount for ``UPDATE`` and ``DELETE`` statements.
Class Variable supports_schemas Undocumented
Class Variable supports_server_side_cursors indicates if the dialect supports server side cursors
Class Variable supports_simple_order_by_label target database supports ORDER BY <labelname>, where <labelname> refers to a label in the columns clause of the SELECT
Class Variable supports_views Undocumented
Class Variable tuple_in_values target database supports tuple IN, i.e. (x, y) IN ((q, p), (r, z))
Class Variable update_executemany_returning dialect supports UPDATE..RETURNING with executemany.
Instance Variable bind_typing Undocumented
Instance Variable compiler_linting Undocumented
Instance Variable dbapi A reference to the DBAPI module object itself.
Instance Variable default_isolation_level the isolation that is implicitly present on new connections
Instance Variable default_schema_name the name of the default schema. This value is only available for supporting dialects, and is typically populated during the initial connection to the database.
Instance Variable identifier_preparer This element will refer to an instance of :class:`.IdentifierPreparer` once a :class:`.DefaultDialect` has been constructed.
Instance Variable insertmanyvalues_page_size Number of rows to render into an individual INSERT..VALUES() statement for :attr:`.ExecuteStyle.INSERTMANYVALUES` executions.
Instance Variable label_length optional user-defined max length for SQL labels
Instance Variable paramstyle the paramstyle to be used (some DB-APIs support multiple paramstyles).
Instance Variable positional True if the paramstyle for this Dialect is positional.
Instance Variable type_compiler legacy; this is a TypeCompiler class at the class level, a TypeCompiler instance at the instance level.
Instance Variable type_compiler_instance instance of a :class:`.Compiled` class used to compile SQL type objects
Property dialect_description Undocumented
Property full_returning Undocumented
Property insert_executemany_returning dialect / driver / database supports some means of providing INSERT...RETURNING support when dialect.do_executemany() is used.
Property loaded_dbapi same as .dbapi, but is never None; will raise an error if no DBAPI was set up.
Property supports_sane_rowcount_returning True if this dialect supports sane rowcount even if RETURNING is in use.
Method _assert_and_set_isolation_level Undocumented
Method _builtin_onconnect Undocumented
Method _check_max_identifier_length Perform a connection / server version specific check to determine the max_identifier_length.
Method _default_multi_reflect Undocumented
Method _deliver_insertmanyvalues_batches convert executemany parameters for an INSERT into an iterator of statement/single execute values, used by the insertmanyvalues feature.
Method _do_ping_w_event Undocumented
Method _ensure_has_table_connection Undocumented
Method _gen_allowed_isolation_levels Undocumented
Method _overrides_default Undocumented
Method _reset_characteristics Undocumented
Method _set_connection_characteristics Undocumented
Class Variable _legacy_binary_type_literal_encoding Undocumented
Instance Variable _ischema Undocumented
Instance Variable _on_connect_isolation_level Undocumented
Instance Variable _user_defined_max_identifier_length Undocumented
Property _bind_typing_render_casts Undocumented
Property _dialect_specific_select_one Undocumented
Property _supports_statement_cache internal evaluation for supports_statement_cache
Property _type_memos Undocumented

Inherited from Dialect (via DefaultDialect):

Class Method engine_created A convenience hook called before returning the final :class:`_engine.Engine`.
Class Method get_async_dialect_cls Given a URL, return the :class:`.Dialect` that will be used by an async engine.
Class Method get_dialect_cls Given a URL, return the :class:`.Dialect` that will be used.
Class Method import_dbapi Import the DBAPI module that is used by this dialect.
Method do_begin_twophase Begin a two phase transaction on the given connection.
Method do_commit_twophase Commit a two phase transaction on the given connection.
Method do_prepare_twophase Prepare a two phase transaction on the given connection.
Method do_recover_twophase Recover list of uncommitted prepared two phase transaction identifiers on the given connection.
Method do_rollback_twophase Rollback a two phase transaction on the given connection.
Method do_set_input_sizes invoke the cursor.setinputsizes() method with appropriate arguments
Method get_check_constraints Return information about check constraints in ``table_name``.
Method get_materialized_view_names Return a list of all materialized view names available in the database.
Method get_table_options Return a dictionary of options specified when ``table_name`` was created.
Method get_temp_table_names Return a list of temporary table names on the given connection, if supported by the underlying backend.
Method get_temp_view_names Return a list of temporary view names on the given connection, if supported by the underlying backend.
Method get_unique_constraints Return information about unique constraints in ``table_name``.
Method on_connect_url return a callable which sets up a newly created DBAPI connection.
Class Variable ddl_compiler a :class:`.Compiled` class used to compile DDL statements
Class Variable dispatch Undocumented
Class Variable driver identifying name for the dialect's DBAPI
Class Variable execute_sequence_format either the 'tuple' or 'list' type, depending on what cursor.execute() accepts for the second argument (they vary).
Class Variable execution_ctx_cls a :class:`.ExecutionContext` class used to handle statement execution
Class Variable preparer a :class:`.IdentifierPreparer` class used to quote identifiers.
Class Variable reflection_options Sequence of string names indicating keyword arguments that can be established on a :class:`.Table` object which will be passed as "reflection options" when using :paramref:`.Table.autoload_with`.
Class Variable statement_compiler a :class:`.Compiled` class used to compile SQL statements
Class Variable type_compiler_cls a :class:`.Compiled` class used to compile SQL type objects
Method _get_server_version_info Retrieve the server version info from the given connection.
Class Variable _has_events Undocumented
def __init__(self, query_timeout=None, use_scope_identity=True, schema_name='dbo', deprecate_large_types=None, supports_comments=None, json_serializer=None, json_deserializer=None, legacy_schema_aliasing=None, ignore_no_transaction_on_rollback=False, **opts): (source)
overrides sqlalchemy.engine.default.DefaultDialect.__init__
overridden in sqlalchemy.dialects.mssql.pyodbc.MSDialect_pyodbc

Undocumented

def do_release_savepoint(self, connection, name): (source)
overrides sqlalchemy.engine.default.DefaultDialect.do_release_savepoint

Release the named savepoint on a connection. :param connection: a :class:`_engine.Connection`. :param name: savepoint name.

def do_rollback(self, dbapi_connection): (source)
overrides sqlalchemy.engine.default.DefaultDialect.do_rollback

Provide an implementation of ``connection.rollback()``, given a DB-API connection. :param dbapi_connection: a DBAPI connection, typically proxied within a :class:`.ConnectionFairy`.

def do_savepoint(self, connection, name): (source)
overrides sqlalchemy.engine.default.DefaultDialect.do_savepoint

Create a savepoint with the given name. :param connection: a :class:`_engine.Connection`. :param name: savepoint name.

@reflection.cache
@_db_plus_owner
def get_columns(self, connection, tablename, dbname, owner, schema, **kw): (source)
overrides sqlalchemy.engine.interfaces.Dialect.get_columns

Return information about columns in ``table_name``. Given a :class:`_engine.Connection`, a string ``table_name``, and an optional string ``schema``, return column information as a list of dictionaries corresponding to the :class:`.ReflectedColumn` dictionary. This is an internal dialect method. Applications should use :meth:`.Inspector.get_columns`.

@reflection.cache
@_db_plus_owner
def get_foreign_keys(self, connection, tablename, dbname, owner, schema, **kw): (source)
overrides sqlalchemy.engine.interfaces.Dialect.get_foreign_keys

Return information about foreign_keys in ``table_name``. Given a :class:`_engine.Connection`, a string ``table_name``, and an optional string ``schema``, return foreign key information as a list of dicts corresponding to the :class:`.ReflectedForeignKeyConstraint` dictionary. This is an internal dialect method. Applications should use :meth:`_engine.Inspector.get_foreign_keys`.

@reflection.cache
@_db_plus_owner
def get_indexes(self, connection, tablename, dbname, owner, schema, **kw): (source)
overrides sqlalchemy.engine.interfaces.Dialect.get_indexes

Return information about indexes in ``table_name``. Given a :class:`_engine.Connection`, a string ``table_name`` and an optional string ``schema``, return index information as a list of dictionaries corresponding to the :class:`.ReflectedIndex` dictionary. This is an internal dialect method. Applications should use :meth:`.Inspector.get_indexes`.

def get_isolation_level(self, dbapi_connection): (source)
overrides sqlalchemy.engine.interfaces.Dialect.get_isolation_level

Given a DBAPI connection, return its isolation level. When working with a :class:`_engine.Connection` object, the corresponding DBAPI connection may be procured using the :attr:`_engine.Connection.connection` accessor. Note that this is a dialect-level method which is used as part of the implementation of the :class:`_engine.Connection` and :class:`_engine.Engine` isolation level facilities; these APIs should be preferred for most typical use cases. .. seealso:: :meth:`_engine.Connection.get_isolation_level` - view current level :attr:`_engine.Connection.default_isolation_level` - view default level :paramref:`.Connection.execution_options.isolation_level` - set per :class:`_engine.Connection` isolation level :paramref:`_sa.create_engine.isolation_level` - set per :class:`_engine.Engine` isolation level

def get_isolation_level_values(self, dbapi_connection): (source)
overrides sqlalchemy.engine.interfaces.Dialect.get_isolation_level_values
overridden in sqlalchemy.dialects.mssql.pymssql.MSDialect_pymssql

return a sequence of string isolation level names that are accepted by this dialect. The available names should use the following conventions: * use UPPERCASE names. isolation level methods will accept lowercase names but these are normalized into UPPERCASE before being passed along to the dialect. * separate words should be separated by spaces, not underscores, e.g. ``REPEATABLE READ``. isolation level names will have underscores converted to spaces before being passed along to the dialect. * The names for the four standard isolation names to the extent that they are supported by the backend should be ``READ UNCOMMITTED`` ``READ COMMITTED``, ``REPEATABLE READ``, ``SERIALIZABLE`` * if the dialect supports an autocommit option it should be provided using the isolation level name ``AUTOCOMMIT``. * Other isolation modes may also be present, provided that they are named in UPPERCASE and use spaces not underscores. This function is used so that the default dialect can check that a given isolation level parameter is valid, else raises an :class:`_exc.ArgumentError`. A DBAPI connection is passed to the method, in the unlikely event that the dialect needs to interrogate the connection itself to determine this list, however it is expected that most backends will return a hardcoded list of values. If the dialect supports "AUTOCOMMIT", that value should also be present in the sequence returned. The method raises ``NotImplementedError`` by default. If a dialect does not implement this method, then the default dialect will not perform any checking on a given isolation level value before passing it onto the :meth:`.Dialect.set_isolation_level` method. This is to allow backwards-compatibility with third party dialects that may not yet be implementing this method. .. versionadded:: 2.0

@reflection.cache
@_db_plus_owner
def get_pk_constraint(self, connection, tablename, dbname, owner, schema, **kw): (source)
overrides sqlalchemy.engine.interfaces.Dialect.get_pk_constraint

Return information about the primary key constraint on table_name`. Given a :class:`_engine.Connection`, a string ``table_name``, and an optional string ``schema``, return primary key information as a dictionary corresponding to the :class:`.ReflectedPrimaryKeyConstraint` dictionary. This is an internal dialect method. Applications should use :meth:`.Inspector.get_pk_constraint`.

@reflection.cache
def get_schema_names(self, connection, **kw): (source)
overrides sqlalchemy.engine.interfaces.Dialect.get_schema_names

Return a list of all schema names available in the database. This is an internal dialect method. Applications should use :meth:`_engine.Inspector.get_schema_names`.

@reflection.cache
@_db_plus_owner_listing
def get_sequence_names(self, connection, dbname, owner, schema, **kw): (source)
overrides sqlalchemy.engine.interfaces.Dialect.get_sequence_names

Return a list of all sequence names available in the database. This is an internal dialect method. Applications should use :meth:`_engine.Inspector.get_sequence_names`. :param schema: schema name to query, if not the default schema. .. versionadded:: 1.4

@reflection.cache
def get_table_comment(self, connection, table_name, schema=None, **kw): (source)
overrides sqlalchemy.engine.interfaces.Dialect.get_table_comment

Return the "comment" for the table identified by ``table_name``. Given a string ``table_name`` and an optional string ``schema``, return table comment information as a dictionary corresponding to the :class:`.ReflectedTableComment` dictionary. This is an internal dialect method. Applications should use :meth:`.Inspector.get_table_comment`. :raise: ``NotImplementedError`` for dialects that don't support comments. .. versionadded:: 1.2

@reflection.cache
@_db_plus_owner_listing
def get_table_names(self, connection, dbname, owner, schema, **kw): (source)
overrides sqlalchemy.engine.interfaces.Dialect.get_table_names

Return a list of table names for ``schema``. This is an internal dialect method. Applications should use :meth:`_engine.Inspector.get_table_names`.

@reflection.cache
@_db_plus_owner
def get_view_definition(self, connection, viewname, dbname, owner, schema, **kw): (source)
overrides sqlalchemy.engine.interfaces.Dialect.get_view_definition

Return plain or materialized view definition. This is an internal dialect method. Applications should use :meth:`_engine.Inspector.get_view_definition`. Given a :class:`_engine.Connection`, a string ``view_name``, and an optional string ``schema``, return the view definition.

@reflection.cache
@_db_plus_owner_listing
def get_view_names(self, connection, dbname, owner, schema, **kw): (source)
overrides sqlalchemy.engine.interfaces.Dialect.get_view_names

Return a list of all non-materialized view names available in the database. This is an internal dialect method. Applications should use :meth:`_engine.Inspector.get_view_names`. :param schema: schema name to query, if not the default schema.

@reflection.cache
@_db_plus_owner
def has_sequence(self, connection, sequencename, dbname, owner, schema, **kw): (source)
overrides sqlalchemy.engine.interfaces.Dialect.has_sequence

Check the existence of a particular sequence in the database. Given a :class:`_engine.Connection` object and a string `sequence_name`, return ``True`` if the given sequence exists in the database, ``False`` otherwise. This is an internal dialect method. Applications should use :meth:`_engine.Inspector.has_sequence`.

@_db_plus_owner
def has_table(self, connection, tablename, dbname, owner, schema, **kw): (source)
overrides sqlalchemy.engine.interfaces.Dialect.has_table

For internal dialect use, check the existence of a particular table or view in the database. Given a :class:`_engine.Connection` object, a string table_name and optional schema name, return True if the given table exists in the database, False otherwise. This method serves as the underlying implementation of the public facing :meth:`.Inspector.has_table` method, and is also used internally to implement the "checkfirst" behavior for methods like :meth:`_schema.Table.create` and :meth:`_schema.MetaData.create_all`. .. note:: This method is used internally by SQLAlchemy, and is published so that third-party dialects may provide an implementation. It is **not** the public API for checking for table presence. Please use the :meth:`.Inspector.has_table` method. .. versionchanged:: 2.0:: :meth:`_engine.Dialect.has_table` now formally supports checking for additional table-like objects: * any type of views (plain or materialized) * temporary tables of any kind Previously, these two checks were not formally specified and different dialects would vary in their behavior. The dialect testing suite now includes tests for all of these object types, and dialects to the degree that the backing database supports views or temporary tables should seek to support locating these objects for full compliance.

def initialize(self, connection): (source)
overrides sqlalchemy.engine.default.DefaultDialect.initialize

Called during strategized creation of the dialect with a connection. Allows dialects to configure options based on server version info or other properties. The connection passed here is a SQLAlchemy Connection object, with full capabilities. The initialize() method of the base dialect should be called via super(). .. note:: as of SQLAlchemy 1.4, this method is called **before** any :meth:`_engine.Dialect.on_connect` hooks are called.

def set_isolation_level(self, dbapi_connection, level): (source)
overrides sqlalchemy.engine.interfaces.Dialect.set_isolation_level
overridden in sqlalchemy.dialects.mssql.pymssql.MSDialect_pymssql

Given a DBAPI connection, set its isolation level. Note that this is a dialect-level method which is used as part of the implementation of the :class:`_engine.Connection` and :class:`_engine.Engine` isolation level facilities; these APIs should be preferred for most typical use cases. If the dialect also implements the :meth:`.Dialect.get_isolation_level_values` method, then the given level is guaranteed to be one of the string names within that sequence, and the method will not need to anticipate a lookup failure. .. seealso:: :meth:`_engine.Connection.get_isolation_level` - view current level :attr:`_engine.Connection.default_isolation_level` - view default level :paramref:`.Connection.execution_options.isolation_level` - set per :class:`_engine.Connection` isolation level :paramref:`_sa.create_engine.isolation_level` - set per :class:`_engine.Engine` isolation level

colspecs = (source)
overrides sqlalchemy.engine.default.DefaultDialect.colspecs
overridden in sqlalchemy.dialects.mssql.pymssql.MSDialect_pymssql, sqlalchemy.dialects.mssql.pyodbc.MSDialect_pyodbc

A dictionary of TypeEngine classes from sqlalchemy.types mapped to subclasses that are specific to the dialect class. This dictionary is class-level only and is not accessed from the dialect instance itself.

construct_arguments = (source)
overrides sqlalchemy.engine.interfaces.Dialect.construct_arguments

Optional set of argument specifiers for various SQLAlchemy constructs, typically schema items. To implement, establish as a series of tuples, as in:: construct_arguments = [ (schema.Index, { "using": False, "where": None, "ops": None }) ] If the above construct is established on the PostgreSQL dialect, the :class:`.Index` construct will now accept the keyword arguments ``postgresql_using``, ``postgresql_where``, nad ``postgresql_ops``. Any other argument specified to the constructor of :class:`.Index` which is prefixed with ``postgresql_`` will raise :class:`.ArgumentError`. A dialect which does not include a ``construct_arguments`` member will not participate in the argument validation system. For such a dialect, any argument name is accepted by all participating constructs, within the namespace of arguments prefixed with that dialect name. The rationale here is so that third-party dialects that haven't yet implemented this feature continue to function in the old way. .. versionadded:: 0.9.2 .. seealso:: :class:`.DialectKWArgs` - implementing base class which consumes :attr:`.DefaultDialect.construct_arguments`

default_sequence_base: int = (source)
overrides sqlalchemy.engine.default.DefaultDialect.default_sequence_base

the default value that will be rendered as the "START WITH" portion of a CREATE SEQUENCE DDL statement.

delete_returning: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.delete_returning

if the dialect supports RETURNING with DELETE .. versionadded:: 2.0

delete_returning_multifrom: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.delete_returning_multifrom

if the dialect supports RETURNING with DELETE..FROM .. versionadded:: 2.0

engine_config_types = (source)
overrides sqlalchemy.engine.default.DefaultDialect.engine_config_types

a mapping of string keys that can be in an engine config linked to type conversion functions.

favor_returning_over_lastrowid: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.favor_returning_over_lastrowid

for backends that support both a lastrowid and a RETURNING insert strategy, favor RETURNING for simple single-int pk inserts. cursor.lastrowid tends to be more performant on most backends.

insert_returning: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.insert_returning

if the dialect supports RETURNING with INSERT .. versionadded:: 2.0

insertmanyvalues_max_parameters: int = (source)
overrides sqlalchemy.engine.default.DefaultDialect.insertmanyvalues_max_parameters

Alternate to insertmanyvalues_page_size, will additionally limit page size based on number of parameters total in the statement.

max_identifier_length: int = (source)
overrides sqlalchemy.engine.default.DefaultDialect.max_identifier_length

The maximum length of identifier names.

name: str = (source)
overrides sqlalchemy.engine.default.DefaultDialect.name

identifying name for the dialect from a DBAPI-neutral point of view (i.e. 'sqlite')

non_native_boolean_check_constraint: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.non_native_boolean_check_constraint

Undocumented

postfetch_lastrowid: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.postfetch_lastrowid

Undocumented

sequences_optional: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.sequences_optional

If True, indicates if the :paramref:`_schema.Sequence.optional` parameter on the :class:`_schema.Sequence` construct should signal to not generate a CREATE SEQUENCE. Applies only to dialects that support sequences. Currently used only to allow PostgreSQL SERIAL to be used on a column that specifies Sequence() for usage on other backends.

server_version_info: tuple = (source)
overrides sqlalchemy.engine.default.DefaultDialect.server_version_info

a tuple containing a version number for the DB backend in use. This value is only available for supporting dialects, and is typically populated during the initial connection to the database.

supports_default_metavalue: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.supports_default_metavalue

dialect supports INSERT... VALUES (DEFAULT) syntax - SQL Server **does** support this, but **not** for the IDENTITY column, so we can't turn this on.

supports_default_values: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.supports_default_values

dialect supports INSERT... DEFAULT VALUES syntax

supports_empty_insert: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.supports_empty_insert

dialect supports INSERT () VALUES ()

supports_native_boolean: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.supports_native_boolean

Indicates if the dialect supports a native boolean construct. This will prevent :class:`_types.Boolean` from generating a CHECK constraint when that type is used.

supports_sequences: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.supports_sequences

Indicates if the dialect supports CREATE SEQUENCE or similar.

supports_statement_cache: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.supports_statement_cache
overridden in sqlalchemy.dialects.mssql.pymssql.MSDialect_pymssql, sqlalchemy.dialects.mssql.pyodbc.MSDialect_pyodbc

indicates if this dialect supports caching. All dialects that are compatible with statement caching should set this flag to True directly on each dialect class and subclass that supports it. SQLAlchemy tests that this flag is locally present on each dialect subclass before it will use statement caching. This is to provide safety for legacy or new dialects that are not yet fully tested to be compliant with SQL statement caching. .. versionadded:: 1.4.5 .. seealso:: :ref:`engine_thirdparty_caching`

supports_unicode_binds: bool = (source)

Undocumented

update_returning: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.update_returning

if the dialect supports RETURNING with UPDATE .. versionadded:: 2.0

update_returning_multifrom: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.update_returning_multifrom

if the dialect supports RETURNING with UPDATE..FROM .. versionadded:: 2.0

use_insertmanyvalues: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.use_insertmanyvalues

if True, indicates "insertmanyvalues" functionality should be used to allow for ``insert_executemany_returning`` behavior, if possible. In practice, setting this to True means: if ``supports_multivalues_insert``, ``insert_returning`` and ``use_insertmanyvalues`` are all True, the SQL compiler will produce an INSERT that will be interpreted by the :class:`.DefaultDialect` as an :attr:`.ExecuteStyle.INSERTMANYVALUES` execution that allows for INSERT of many rows with RETURNING by rewriting a single-row INSERT statement to have multiple VALUES clauses, also executing the statement multiple times for a series of batches when large numbers of rows are given. The parameter is False for the default dialect, and is set to True for SQLAlchemy internal dialects SQLite, MySQL/MariaDB, PostgreSQL, SQL Server. It remains at False for Oracle, which provides native "executemany with RETURNING" support and also does not support ``supports_multivalues_insert``. For MySQL/MariaDB, those MySQL dialects that don't support RETURNING will not report ``insert_executemany_returning`` as True. .. versionadded:: 2.0 .. seealso:: :ref:`engine_insertmanyvalues`

use_insertmanyvalues_wo_returning: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.use_insertmanyvalues_wo_returning

if True, and use_insertmanyvalues is also True, INSERT statements that don't include RETURNING will also use "insertmanyvalues". .. versionadded:: 2.0

deprecate_large_types = (source)

Undocumented

ignore_no_transaction_on_rollback = (source)

Undocumented

legacy_schema_aliasing = (source)

Undocumented

query_timeout = (source)

Undocumented

schema_name = (source)

Undocumented

supports_comments = (source)
overrides sqlalchemy.engine.default.DefaultDialect.supports_comments

Indicates the dialect supports comment DDL on tables and columns.

supports_multivalues_insert: bool = (source)
overrides sqlalchemy.engine.default.DefaultDialect.supports_multivalues_insert

Target database supports INSERT...VALUES with multiple value sets, i.e. INSERT INTO table (cols) VALUES (...), (...), (...), ...

use_scope_identity = (source)
overridden in sqlalchemy.dialects.mssql.pyodbc.MSDialect_pyodbc

Undocumented

def _default_or_error(self, connection, tablename, owner, method, **kw): (source)

Undocumented

def _get_default_schema_name(self, connection): (source)
overrides sqlalchemy.engine.interfaces.Dialect._get_default_schema_name

Return the string name of the currently selected schema from the given connection. This is used by the default implementation to populate the "default_schema_name" attribute and is called exactly once upon first connect.

def _get_internal_temp_table_name(self, connection, tablename): (source)

Undocumented

@reflection.cache
def _internal_has_table(self, connection, tablename, owner, **kw): (source)

Undocumented

def _setup_supports_comments(self, connection): (source)

Undocumented

def _setup_supports_nvarchar_max(self, connection): (source)

Undocumented

def _setup_version_attributes(self): (source)

Undocumented

def _temp_table_name_like_pattern(self, tablename): (source)

Undocumented

_isolation_lookup: set[str] = (source)

Undocumented

_supports_nvarchar_max: bool = (source)

Undocumented

_json_deserializer = (source)

Undocumented

_json_serializer = (source)

Undocumented

_supports_offset_fetch = (source)

Undocumented

_user_defined_supports_comments = (source)

Undocumented