1 files changed, 232 insertions, 0 deletions
diff --git a/lib/sqlalchemy/dialects/mssql/information_schema.py b/lib/sqlalchemy/dialects/mssql/information_schema.py
new file mode 100644
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--- /dev/null
+++ b/lib/sqlalchemy/dialects/mssql/information_schema.py
@@ -0,0 +1,232 @@
+# mssql/information_schema.py
+# Copyright (C) 2005-2022 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
+
+from ... import cast
+from ... import Column
+from ... import MetaData
+from ... import Table
+from ... import util
+from ...ext.compiler import compiles
+from ...sql import expression
+from ...types import Boolean
+from ...types import Integer
+from ...types import Numeric
+from ...types import String
+from ...types import TypeDecorator
+from ...types import Unicode
+
+
+ischema = MetaData()
+
+
+class CoerceUnicode(TypeDecorator):
+    impl = Unicode
+    cache_ok = True
+
+    def process_bind_param(self, value, dialect):
+        if util.py2k and isinstance(value, util.binary_type):
+            value = value.decode(dialect.encoding)
+        return value
+
+    def bind_expression(self, bindvalue):
+        return _cast_on_2005(bindvalue)
+
+
+class _cast_on_2005(expression.ColumnElement):
+    def __init__(self, bindvalue):
+        self.bindvalue = bindvalue
+
+
+@compiles(_cast_on_2005)
+def _compile(element, compiler, **kw):
+    from . import base
+
+    if (
+        compiler.dialect.server_version_info is None
+        or compiler.dialect.server_version_info < base.MS_2005_VERSION
+    ):
+        return compiler.process(element.bindvalue, **kw)
+    else:
+        return compiler.process(cast(element.bindvalue, Unicode), **kw)
+
+
+schemata = Table(
+    "SCHEMATA",
+    ischema,
+    Column("CATALOG_NAME", CoerceUnicode, key="catalog_name"),
+    Column("SCHEMA_NAME", CoerceUnicode, key="schema_name"),
+    Column("SCHEMA_OWNER", CoerceUnicode, key="schema_owner"),
+    schema="INFORMATION_SCHEMA",
+)
+
+tables = Table(
+    "TABLES",
+    ischema,
+    Column("TABLE_CATALOG", CoerceUnicode, key="table_catalog"),
+    Column("TABLE_SCHEMA", CoerceUnicode, key="table_schema"),
+    Column("TABLE_NAME", CoerceUnicode, key="table_name"),
+    Column("TABLE_TYPE", CoerceUnicode, key="table_type"),
+    schema="INFORMATION_SCHEMA",
+)
+
+columns = Table(
+    "COLUMNS",
+    ischema,
+    Column("TABLE_SCHEMA", CoerceUnicode, key="table_schema"),
+    Column("TABLE_NAME", CoerceUnicode, key="table_name"),
+    Column("COLUMN_NAME", CoerceUnicode, key="column_name"),
+    Column("IS_NULLABLE", Integer, key="is_nullable"),
+    Column("DATA_TYPE", String, key="data_type"),
+    Column("ORDINAL_POSITION", Integer, key="ordinal_position"),
+    Column(
+        "CHARACTER_MAXIMUM_LENGTH", Integer, key="character_maximum_length"
+    ),
+    Column("NUMERIC_PRECISION", Integer, key="numeric_precision"),
+    Column("NUMERIC_SCALE", Integer, key="numeric_scale"),
+    Column("COLUMN_DEFAULT", Integer, key="column_default"),
+    Column("COLLATION_NAME", String, key="collation_name"),
+    schema="INFORMATION_SCHEMA",
+)
+
+mssql_temp_table_columns = Table(
+    "COLUMNS",
+    ischema,
+    Column("TABLE_SCHEMA", CoerceUnicode, key="table_schema"),
+    Column("TABLE_NAME", CoerceUnicode, key="table_name"),
+    Column("COLUMN_NAME", CoerceUnicode, key="column_name"),
+    Column("IS_NULLABLE", Integer, key="is_nullable"),
+    Column("DATA_TYPE", String, key="data_type"),
+    Column("ORDINAL_POSITION", Integer, key="ordinal_position"),
+    Column(
+        "CHARACTER_MAXIMUM_LENGTH", Integer, key="character_maximum_length"
+    ),
+    Column("NUMERIC_PRECISION", Integer, key="numeric_precision"),
+    Column("NUMERIC_SCALE", Integer, key="numeric_scale"),
+    Column("COLUMN_DEFAULT", Integer, key="column_default"),
+    Column("COLLATION_NAME", String, key="collation_name"),
+    schema="tempdb.INFORMATION_SCHEMA",
+)
+
+constraints = Table(
+    "TABLE_CONSTRAINTS",
+    ischema,
+    Column("TABLE_SCHEMA", CoerceUnicode, key="table_schema"),
+    Column("TABLE_NAME", CoerceUnicode, key="table_name"),
+    Column("CONSTRAINT_NAME", CoerceUnicode, key="constraint_name"),
+    Column("CONSTRAINT_TYPE", CoerceUnicode, key="constraint_type"),
+    schema="INFORMATION_SCHEMA",
+)
+
+column_constraints = Table(
+    "CONSTRAINT_COLUMN_USAGE",
+    ischema,
+    Column("TABLE_SCHEMA", CoerceUnicode, key="table_schema"),
+    Column("TABLE_NAME", CoerceUnicode, key="table_name"),
+    Column("COLUMN_NAME", CoerceUnicode, key="column_name"),
+    Column("CONSTRAINT_NAME", CoerceUnicode, key="constraint_name"),
+    schema="INFORMATION_SCHEMA",
+)
+
+key_constraints = Table(
+    "KEY_COLUMN_USAGE",
+    ischema,
+    Column("TABLE_SCHEMA", CoerceUnicode, key="table_schema"),
+    Column("TABLE_NAME", CoerceUnicode, key="table_name"),
+    Column("COLUMN_NAME", CoerceUnicode, key="column_name"),
+    Column("CONSTRAINT_NAME", CoerceUnicode, key="constraint_name"),
+    Column("CONSTRAINT_SCHEMA", CoerceUnicode, key="constraint_schema"),
+    Column("ORDINAL_POSITION", Integer, key="ordinal_position"),
+    schema="INFORMATION_SCHEMA",
+)
+
+ref_constraints = Table(
+    "REFERENTIAL_CONSTRAINTS",
+    ischema,
+    Column("CONSTRAINT_CATALOG", CoerceUnicode, key="constraint_catalog"),
+    Column("CONSTRAINT_SCHEMA", CoerceUnicode, key="constraint_schema"),
+    Column("CONSTRAINT_NAME", CoerceUnicode, key="constraint_name"),
+    # TODO: is CATLOG misspelled ?
+    Column(
+        "UNIQUE_CONSTRAINT_CATLOG",
+        CoerceUnicode,
+        key="unique_constraint_catalog",
+    ),
+    Column(
+        "UNIQUE_CONSTRAINT_SCHEMA",
+        CoerceUnicode,
+        key="unique_constraint_schema",
+    ),
+    Column(
+        "UNIQUE_CONSTRAINT_NAME", CoerceUnicode, key="unique_constraint_name"
+    ),
+    Column("MATCH_OPTION", String, key="match_option"),
+    Column("UPDATE_RULE", String, key="update_rule"),
+    Column("DELETE_RULE", String, key="delete_rule"),
+    schema="INFORMATION_SCHEMA",
+)
+
+views = Table(
+    "VIEWS",
+    ischema,
+    Column("TABLE_CATALOG", CoerceUnicode, key="table_catalog"),
+    Column("TABLE_SCHEMA", CoerceUnicode, key="table_schema"),
+    Column("TABLE_NAME", CoerceUnicode, key="table_name"),
+    Column("VIEW_DEFINITION", CoerceUnicode, key="view_definition"),
+    Column("CHECK_OPTION", String, key="check_option"),
+    Column("IS_UPDATABLE", String, key="is_updatable"),
+    schema="INFORMATION_SCHEMA",
+)
+
+computed_columns = Table(
+    "computed_columns",
+    ischema,
+    Column("object_id", Integer),
+    Column("name", CoerceUnicode),
+    Column("is_computed", Boolean),
+    Column("is_persisted", Boolean),
+    Column("definition", CoerceUnicode),
+    schema="sys",
+)
+
+sequences = Table(
+    "SEQUENCES",
+    ischema,
+    Column("SEQUENCE_CATALOG", CoerceUnicode, key="sequence_catalog"),
+    Column("SEQUENCE_SCHEMA", CoerceUnicode, key="sequence_schema"),
+    Column("SEQUENCE_NAME", CoerceUnicode, key="sequence_name"),
+    schema="INFORMATION_SCHEMA",
+)
+
+
+class IdentitySqlVariant(TypeDecorator):
+    r"""This type casts sql_variant columns in the identity_columns view
+    to numeric. This is required because:
+
+    * pyodbc does not support sql_variant
+    * pymssql under python 2 return the byte representation of the number,
+      int 1 is returned as "\x01\x00\x00\x00". On python 3 it returns the
+      correct value as string.
+    """
+    impl = Unicode
+    cache_ok = True
+
+    def column_expression(self, colexpr):
+        return cast(colexpr, Numeric)
+
+
+identity_columns = Table(
+    "identity_columns",
+    ischema,
+    Column("object_id", Integer),
+    Column("name", CoerceUnicode),
+    Column("is_identity", Boolean),
+    Column("seed_value", IdentitySqlVariant),
+    Column("increment_value", IdentitySqlVariant),
+    Column("last_value", IdentitySqlVariant),
+    Column("is_not_for_replication", Boolean),
+    schema="sys",
+)