FEAT: Adding setinputsizes (#192)

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[AB#32890](https://sqlclientdrivers.visualstudio.com/c6d89619-62de-46a0-8b46-70b92a84d85e/_workitems/edit/32890)

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### Summary   
This pull request adds comprehensive support for advanced SQL metadata
and catalog functions to the MSSQL Python bindings, making it easier to
interact with database schema information and supported data types from
Python. The changes include new wrapper functions and Python bindings
for several ODBC catalog APIs, the addition of SQL type constants, and
enhancements to the constants module for easier type validation and
categorization.

### SQL Catalog & Metadata API Support

* Added wrapper functions and Python bindings for ODBC catalog APIs:
`SQLGetTypeInfo`, `SQLProcedures`, `SQLForeignKeys`, `SQLPrimaryKeys`,
`SQLSpecialColumns`, `SQLStatistics`, and `SQLColumns` in
`ddbc_bindings.cpp`. These allow Python code to directly query metadata
about tables, columns, keys, procedures, and supported types.

### Constants and Type Handling

* Exported SQL type constants (e.g., `SQL_CHAR`, `SQL_INTEGER`, etc.) at
the module level in `__init__.py` for easier use in Python code.
* Added new constants to `ConstantsDDBC` for catalog API parameters such
as `SQL_SCOPE_CURROW`, `SQL_BEST_ROWID`, `SQL_ROWVER`, and others.
* Introduced the `SQLTypes` class in `constants.py`, providing methods
to retrieve sets of valid SQL types and categorize them (e.g., string
types, numeric types), which can help with input validation and type
checking in Python.

These changes significantly improve the ability of Python applications
to introspect and work with database schema and type information, making
your code more robust and flexible when dealing with SQL Server
databases.

---------

Co-authored-by: Jahnvi Thakkar <jathakkar@microsoft.com>

Author: jahnvi480

mssql_python/__init__.py

@@ -180,3 +180,28 @@ def _custom_setattr(name, value):
 
 # Replace the module's __setattr__ with our custom version
 sys.modules[__name__].__setattr__ = _custom_setattr
+
+
+# Export SQL constants at module level
+SQL_CHAR = ConstantsDDBC.SQL_CHAR.value
+SQL_VARCHAR = ConstantsDDBC.SQL_VARCHAR.value
+SQL_LONGVARCHAR = ConstantsDDBC.SQL_LONGVARCHAR.value
+SQL_WCHAR = ConstantsDDBC.SQL_WCHAR.value
+SQL_WVARCHAR = ConstantsDDBC.SQL_WVARCHAR.value
+SQL_WLONGVARCHAR = ConstantsDDBC.SQL_WLONGVARCHAR.value
+SQL_DECIMAL = ConstantsDDBC.SQL_DECIMAL.value
+SQL_NUMERIC = ConstantsDDBC.SQL_NUMERIC.value
+SQL_BIT = ConstantsDDBC.SQL_BIT.value
+SQL_TINYINT = ConstantsDDBC.SQL_TINYINT.value
+SQL_SMALLINT = ConstantsDDBC.SQL_SMALLINT.value
+SQL_INTEGER = ConstantsDDBC.SQL_INTEGER.value
+SQL_BIGINT = ConstantsDDBC.SQL_BIGINT.value
+SQL_REAL = ConstantsDDBC.SQL_REAL.value
+SQL_FLOAT = ConstantsDDBC.SQL_FLOAT.value
+SQL_DOUBLE = ConstantsDDBC.SQL_DOUBLE.value
+SQL_BINARY = ConstantsDDBC.SQL_BINARY.value
+SQL_VARBINARY = ConstantsDDBC.SQL_VARBINARY.value
+SQL_LONGVARBINARY = ConstantsDDBC.SQL_LONGVARBINARY.value
+SQL_DATE = ConstantsDDBC.SQL_DATE.value
+SQL_TIME = ConstantsDDBC.SQL_TIME.value
+SQL_TIMESTAMP = ConstantsDDBC.SQL_TIMESTAMP.value

mssql_python/constants.py

@@ -124,9 +124,63 @@ class ConstantsDDBC(Enum):
     SQL_FETCH_ABSOLUTE = 5
     SQL_FETCH_RELATIVE = 6
     SQL_FETCH_BOOKMARK = 8
+    SQL_SCOPE_CURROW = 0
+    SQL_BEST_ROWID = 1
+    SQL_ROWVER = 2
+    SQL_NO_NULLS = 0
+    SQL_NULLABLE_UNKNOWN = 2
+    SQL_INDEX_UNIQUE = 0
+    SQL_INDEX_ALL = 1
+    SQL_QUICK = 0
+    SQL_ENSURE = 1
 
 class AuthType(Enum):
     """Constants for authentication types"""
     INTERACTIVE = "activedirectoryinteractive"
     DEVICE_CODE = "activedirectorydevicecode"
-    DEFAULT = "activedirectorydefault"
+    DEFAULT = "activedirectorydefault"
+
+class SQLTypes:
+    """Constants for valid SQL data types to use with setinputsizes"""
+    
+    @classmethod
+    def get_valid_types(cls) -> set:
+        """Returns a set of all valid SQL type constants"""
+        
+        return {
+            ConstantsDDBC.SQL_CHAR.value, ConstantsDDBC.SQL_VARCHAR.value, 
+            ConstantsDDBC.SQL_LONGVARCHAR.value, ConstantsDDBC.SQL_WCHAR.value,
+            ConstantsDDBC.SQL_WVARCHAR.value, ConstantsDDBC.SQL_WLONGVARCHAR.value,
+            ConstantsDDBC.SQL_DECIMAL.value, ConstantsDDBC.SQL_NUMERIC.value, 
+            ConstantsDDBC.SQL_BIT.value, ConstantsDDBC.SQL_TINYINT.value,
+            ConstantsDDBC.SQL_SMALLINT.value, ConstantsDDBC.SQL_INTEGER.value, 
+            ConstantsDDBC.SQL_BIGINT.value, ConstantsDDBC.SQL_REAL.value,
+            ConstantsDDBC.SQL_FLOAT.value, ConstantsDDBC.SQL_DOUBLE.value, 
+            ConstantsDDBC.SQL_BINARY.value, ConstantsDDBC.SQL_VARBINARY.value,
+            ConstantsDDBC.SQL_LONGVARBINARY.value, ConstantsDDBC.SQL_DATE.value, 
+            ConstantsDDBC.SQL_TIME.value, ConstantsDDBC.SQL_TIMESTAMP.value,
+            ConstantsDDBC.SQL_GUID.value
+        }
+    
+    # Could also add category methods for convenience
+    @classmethod
+    def get_string_types(cls) -> set:
+        """Returns a set of string SQL type constants"""
+        
+        return {
+            ConstantsDDBC.SQL_CHAR.value, ConstantsDDBC.SQL_VARCHAR.value, 
+            ConstantsDDBC.SQL_LONGVARCHAR.value, ConstantsDDBC.SQL_WCHAR.value,
+            ConstantsDDBC.SQL_WVARCHAR.value, ConstantsDDBC.SQL_WLONGVARCHAR.value
+        }
+    
+    @classmethod
+    def get_numeric_types(cls) -> set:
+        """Returns a set of numeric SQL type constants"""
+        
+        return {
+            ConstantsDDBC.SQL_DECIMAL.value, ConstantsDDBC.SQL_NUMERIC.value,
+            ConstantsDDBC.SQL_BIT.value, ConstantsDDBC.SQL_TINYINT.value,
+            ConstantsDDBC.SQL_SMALLINT.value, ConstantsDDBC.SQL_INTEGER.value,
+            ConstantsDDBC.SQL_BIGINT.value, ConstantsDDBC.SQL_REAL.value,
+            ConstantsDDBC.SQL_FLOAT.value, ConstantsDDBC.SQL_DOUBLE.value
+        }