feat: add spatial type support (geography, geometry, hierarchyid)

Add SQL_SS_UDT (-151) handling so geography, geometry, and hierarchyid
columns are fetched as bytes instead of raising errors.

C++ changes (ddbc_bindings.cpp):
- Define SQL_SS_UDT constant
- Add case fallthroughs to SQL_BINARY in SQLGetData_wrap, SQLBindColums,
  and FetchBatchData
- Separate calculateRowSize case with LOB-size fallback
- Include SQL_SS_UDT in LOB detection for FetchMany_wrap and FetchAll_wrap

Python changes:
- constants.py: SQL_SS_UDT = -151 in ConstantsDDBC enum
- cursor.py: SQL_SS_UDT -> SQL_C_BINARY in sql_to_c_type map
- cursor.py: SQL_SS_UDT -> bytes in sql_to_python_type map

Tests:
- 37 tests covering all three UDT types (geography, geometry, hierarchyid)
- Fetch paths: fetchone, fetchmany, fetchall, executemany
- NULL handling, mixed columns, binary round-trips, error cases
- Output converter and cursor.description metadata verification

Author: dlevy-msft-sql

mssql_python/constants.py

@@ -114,6 +114,7 @@ class ConstantsDDBC(Enum):
     SQL_FETCH_ABSOLUTE = 5
     SQL_FETCH_RELATIVE = 6
     SQL_FETCH_BOOKMARK = 8
+    SQL_SS_UDT = -151
     SQL_DATETIMEOFFSET = -155
     SQL_C_SS_TIMESTAMPOFFSET = 0x4001
     SQL_SCOPE_CURROW = 0
@@ -363,6 +364,7 @@ def get_valid_types(cls) -> set:
             ConstantsDDBC.SQL_TIME.value,
             ConstantsDDBC.SQL_TIMESTAMP.value,
             ConstantsDDBC.SQL_GUID.value,
+            ConstantsDDBC.SQL_SS_UDT.value,
         }
 
     # Could also add category methods for convenience

mssql_python/cursor.py

@@ -865,6 +865,7 @@ def _get_c_type_for_sql_type(self, sql_type: int) -> int:
             ddbc_sql_const.SQL_BINARY.value: ddbc_sql_const.SQL_C_BINARY.value,
             ddbc_sql_const.SQL_VARBINARY.value: ddbc_sql_const.SQL_C_BINARY.value,
             ddbc_sql_const.SQL_LONGVARBINARY.value: ddbc_sql_const.SQL_C_BINARY.value,
+            ddbc_sql_const.SQL_SS_UDT.value: ddbc_sql_const.SQL_C_BINARY.value,
             ddbc_sql_const.SQL_DATE.value: ddbc_sql_const.SQL_C_TYPE_DATE.value,
             ddbc_sql_const.SQL_TIME.value: ddbc_sql_const.SQL_C_TYPE_TIME.value,
             ddbc_sql_const.SQL_TIMESTAMP.value: ddbc_sql_const.SQL_C_TYPE_TIMESTAMP.value,
@@ -1052,6 +1053,7 @@ def _map_data_type(self, sql_type):
             ddbc_sql_const.SQL_BINARY.value: bytes,
             ddbc_sql_const.SQL_VARBINARY.value: bytes,
             ddbc_sql_const.SQL_LONGVARBINARY.value: bytes,
+            ddbc_sql_const.SQL_SS_UDT.value: bytes,
             ddbc_sql_const.SQL_GUID.value: uuid.UUID,
             # Add more mappings as needed
         }

mssql_python/pybind/ddbc_bindings.cpp

@@ -27,6 +27,7 @@
 #define MAX_DIGITS_IN_NUMERIC 64
 #define SQL_MAX_NUMERIC_LEN 16
 #define SQL_SS_XML (-152)
+#define SQL_SS_UDT (-151)
 
 #define STRINGIFY_FOR_CASE(x)                                                                      \
     case x:                                                                                        \
@@ -3285,6 +3286,7 @@ SQLRETURN SQLGetData_wrap(SqlHandlePtr StatementHandle, SQLUSMALLINT colCount, p
                 }
                 break;
             }
+            case SQL_SS_UDT:
             case SQL_BINARY:
             case SQL_VARBINARY:
             case SQL_LONGVARBINARY: {
@@ -3555,6 +3557,7 @@ SQLRETURN SQLBindColums(SQLHSTMT hStmt, ColumnBuffers& buffers, py::list& column
                 ret = SQLBindCol_ptr(hStmt, col, SQL_C_GUID, buffers.guidBuffers[col - 1].data(),
                                      sizeof(SQLGUID), buffers.indicators[col - 1].data());
                 break;
+            case SQL_SS_UDT:
             case SQL_BINARY:
             case SQL_VARBINARY:
             case SQL_LONGVARBINARY:
@@ -3683,6 +3686,7 @@ SQLRETURN FetchBatchData(SQLHSTMT hStmt, ColumnBuffers& buffers, py::list& colum
             case SQL_WLONGVARCHAR:
                 columnProcessors[col] = ColumnProcessors::ProcessWChar;
                 break;
+            case SQL_SS_UDT:
             case SQL_BINARY:
             case SQL_VARBINARY:
             case SQL_LONGVARBINARY:
@@ -3981,6 +3985,10 @@ size_t calculateRowSize(py::list& columnNames, SQLUSMALLINT numCols) {
             case SQL_BIT:
                 rowSize += sizeof(SQLCHAR);
                 break;
+            case SQL_SS_UDT:
+                rowSize += (columnSize == SQL_NO_TOTAL || columnSize == 0)
+                               ? SQL_MAX_LOB_SIZE : columnSize;
+                break;
             case SQL_BINARY:
             case SQL_VARBINARY:
             case SQL_LONGVARBINARY:
@@ -4043,7 +4051,8 @@ SQLRETURN FetchMany_wrap(SqlHandlePtr StatementHandle, py::list& rows, int fetch
 
         if ((dataType == SQL_WVARCHAR || dataType == SQL_WLONGVARCHAR || dataType == SQL_VARCHAR ||
              dataType == SQL_LONGVARCHAR || dataType == SQL_VARBINARY ||
-             dataType == SQL_LONGVARBINARY || dataType == SQL_SS_XML) &&
+             dataType == SQL_LONGVARBINARY || dataType == SQL_SS_XML ||
+             dataType == SQL_SS_UDT) &&
             (columnSize == 0 || columnSize == SQL_NO_TOTAL || columnSize > SQL_MAX_LOB_SIZE)) {
             lobColumns.push_back(i + 1);  // 1-based
         }
@@ -4177,7 +4186,8 @@ SQLRETURN FetchAll_wrap(SqlHandlePtr StatementHandle, py::list& rows,
 
         if ((dataType == SQL_WVARCHAR || dataType == SQL_WLONGVARCHAR || dataType == SQL_VARCHAR ||
              dataType == SQL_LONGVARCHAR || dataType == SQL_VARBINARY ||
-             dataType == SQL_LONGVARBINARY || dataType == SQL_SS_XML) &&
+             dataType == SQL_LONGVARBINARY || dataType == SQL_SS_XML ||
+             dataType == SQL_SS_UDT) &&
             (columnSize == 0 || columnSize == SQL_NO_TOTAL || columnSize > SQL_MAX_LOB_SIZE)) {
             lobColumns.push_back(i + 1);  // 1-based
         }