Merge pull request #31 from pangpang20/master

GaussDB Compatibility Improvements

Author: 5xuanwen

.gitignore

@@ -9,6 +9,8 @@ __pycache__/
 /gaussdb_binary/
 .vscode
 .venv
+myenv
+activate_dev.ps1
 .coverage
 htmlcov
 .idea

gaussdb/gaussdb/_connection_info.py

@@ -11,7 +11,6 @@
 
 from . import pq
 from ._tz import get_tzinfo
-from .conninfo import make_conninfo
 
 
 class ConnectionInfo:
@@ -72,26 +71,74 @@ def get_parameters(self) -> dict[str, str]:
         either from the connection string and parameters passed to
         `~Connection.connect()` or from environment variables. The password
         is never returned (you can read it using the `password` attribute).
+
+        Note:
+            GaussDB does not support PGconn.info attribute, uses fallback method.
         """
         pyenc = self.encoding
 
-        # Get the known defaults to avoid reporting them
-        defaults = {
-            i.keyword: i.compiled
-            for i in pq.Conninfo.get_defaults()
-            if i.compiled is not None
-        }
-        # Not returned by the libq. Bug? Bet we're using SSH.
-        defaults.setdefault(b"channel_binding", b"prefer")
-        defaults[b"passfile"] = str(Path.home() / ".pgpass").encode()
-
-        return {
-            i.keyword.decode(pyenc): i.val.decode(pyenc)
-            for i in self.pgconn.info
-            if i.val is not None
-            and i.keyword != b"password"
-            and i.val != defaults.get(i.keyword)
-        }
+        # Check if info attribute is supported (GaussDB does not support)
+        try:
+            info = self.pgconn.info
+            if info is None:
+                return self._get_parameters_fallback()
+        except (AttributeError, NotImplementedError):
+            return self._get_parameters_fallback()
+
+        # PostgreSQL normal path
+        try:
+            # Get the known defaults to avoid reporting them
+            defaults = {
+                i.keyword: i.compiled
+                for i in pq.Conninfo.get_defaults()
+                if i.compiled is not None
+            }
+            # Not returned by the libq. Bug? Bet we're using SSH.
+            defaults.setdefault(b"channel_binding", b"prefer")
+            defaults[b"passfile"] = str(Path.home() / ".pgpass").encode()
+
+            return {
+                i.keyword.decode(pyenc): i.val.decode(pyenc)
+                for i in info
+                if i.val is not None
+                and i.keyword != b"password"
+                and i.val != defaults.get(i.keyword)
+            }
+        except Exception:
+            # Use fallback on error
+            return self._get_parameters_fallback()
+
+    def _get_parameters_fallback(self) -> dict[str, str]:
+        """Fallback method for getting connection parameters.
+
+        When PGconn.info is not available (e.g., GaussDB),
+        retrieve basic connection information from other sources.
+        """
+        params = {}
+
+        # Get available information from pgconn attributes
+        if self.pgconn.host:
+            params["host"] = self.pgconn.host.decode(self.encoding, errors="replace")
+
+        if self.pgconn.port:
+            params["port"] = self.pgconn.port.decode(self.encoding, errors="replace")
+
+        if self.pgconn.db:
+            params["dbname"] = self.pgconn.db.decode(self.encoding, errors="replace")
+
+        if self.pgconn.user:
+            params["user"] = self.pgconn.user.decode(self.encoding, errors="replace")
+
+        # Get other available parameters
+        try:
+            if hasattr(self.pgconn, "options") and self.pgconn.options:
+                params["options"] = self.pgconn.options.decode(
+                    self.encoding, errors="replace"
+                )
+        except Exception:
+            pass
+
+        return params
 
     @property
     def dsn(self) -> str:
@@ -103,7 +150,25 @@ def dsn(self) -> str:
         password is never returned (you can read it using the `password`
         attribute).
         """
-        return make_conninfo(**self.get_parameters())
+        try:
+            params = self.get_parameters()
+        except Exception:
+            params = self._get_parameters_fallback()
+
+        if not params:
+            return ""
+
+        # Build DSN string
+        parts = []
+        for key, value in params.items():
+            if key == "password":
+                continue  # Do not include password
+            # Escape values
+            if " " in value or "=" in value or "'" in value:
+                value = "'" + value.replace("'", "\\'") + "'"
+            parts.append(f"{key}={value}")
+
+        return " ".join(parts)
 
     @property
     def status(self) -> pq.ConnStatus:

gaussdb/gaussdb/_oids.py

@@ -122,3 +122,55 @@
 YEAR_OID = 1038
 
 # autogenerated: end
+
+
+# =====================================================
+# GaussDB OID 别名映射（PostgreSQL OID -> GaussDB 等效 OID 列表）
+# =====================================================
+
+GAUSSDB_OID_ALIASES: dict[int, list[int]] = {
+    # date 类型可能映射到多个 OID
+    DATE_OID: [DATE_OID, SMALLDATETIME_OID],
+    # timestamp 类型
+    TIMESTAMP_OID: [TIMESTAMP_OID, SMALLDATETIME_OID],
+    TIMESTAMPTZ_OID: [TIMESTAMPTZ_OID],
+    # 其他类型保持一对一映射
+}
+
+
+def is_compatible_oid(expected_oid: int, actual_oid: int) -> bool:
+    """
+    检查两个 OID 是否兼容
+
+    用于 GaussDB 场景下的类型比较，考虑 OID 别名。
+
+    Args:
+        expected_oid: 期望的 OID
+        actual_oid: 实际的 OID
+
+    Returns:
+        是否兼容
+    """
+    if expected_oid == actual_oid:
+        return True
+
+    # 检查别名映射
+    aliases = GAUSSDB_OID_ALIASES.get(expected_oid, [expected_oid])
+    return actual_oid in aliases
+
+
+def get_oid_name(oid: int) -> str:
+    """
+    获取 OID 对应的类型名称
+
+    Args:
+        oid: 类型 OID
+
+    Returns:
+        类型名称字符串
+    """
+    # 反向查找 OID 常量名
+    for name, value in globals().items():
+        if name.endswith("_OID") and value == oid:
+            return name.replace("_OID", "").lower()
+    return f"oid_{oid}"

gaussdb/gaussdb/_py_transformer.py

@@ -38,6 +38,33 @@
 PY_TEXT = PyFormat.TEXT
 
 
+def _is_empty_value(val: Any) -> bool:
+    """检测值是否为等效空值（GaussDB 兼容）"""
+    if val is None:
+        return True
+    if isinstance(val, (bytes, str)) and len(val) == 0:
+        return True
+    if isinstance(val, (dict, list)) and len(val) == 0:
+        return True
+    return False
+
+
+def _normalize_empty_value(val: Any, normalize_to_none: bool = False) -> Any:
+    """
+    将空值规范化处理
+
+    Args:
+        val: 要处理的值
+        normalize_to_none: 如果为 True，将空字符串/空字典等转为 None
+
+    Returns:
+        规范化后的值
+    """
+    if normalize_to_none and _is_empty_value(val):
+        return None
+    return val
+
+
 class Transformer(AdaptContext):
     """
     An object that can adapt efficiently between Python and GaussDB.

gaussdb/gaussdb/_typeinfo.py

@@ -16,6 +16,7 @@
 from . import sql
 from .abc import AdaptContext, Query
 from .rows import dict_row
+from ._oids import GAUSSDB_OID_ALIASES
 from ._compat import TypeAlias, TypeVar
 from ._typemod import TypeModifier
 from ._encodings import conn_encoding
@@ -209,6 +210,56 @@ def get_precision(self, fmod: int) -> int | None:
     def get_scale(self, fmod: int) -> int | None:
         return self.typemod.get_scale(fmod)
 
+    @classmethod
+    def fetch_runtime_oid(cls, conn: Any, typename: str) -> int | None:
+        """
+        运行时获取类型 OID
+
+        从数据库查询正确的 OID，处理 GaussDB 差异。
+
+        Args:
+            conn: 数据库连接
+            typename: 类型名称
+
+        Returns:
+            类型 OID，查询失败返回 None
+        """
+        try:
+            from .connection import Connection
+
+            if isinstance(conn, Connection):
+                result = conn.execute(
+                    "SELECT oid FROM pg_type WHERE typname = %s", [typename]
+                ).fetchone()
+            else:
+                # AsyncConnection
+                import asyncio
+
+                async def _fetch():
+                    result = await conn.execute(
+                        "SELECT oid FROM pg_type WHERE typname = %s", [typename]
+                    )
+                    return await result.fetchone()
+
+                result = asyncio.run(_fetch())
+
+            return result[0] if result else None
+        except Exception:
+            return None
+
+    @classmethod
+    def get_compatible_oids(cls, base_oid: int) -> list[int]:
+        """
+        获取兼容的 OID 列表
+
+        Args:
+            base_oid: 基础 OID
+
+        Returns:
+            包含基础 OID 及其别名的列表
+        """
+        return GAUSSDB_OID_ALIASES.get(base_oid, [base_oid])
+
 
 class TypesRegistry:
     """

gaussdb/gaussdb/raw_cursor.py

@@ -8,6 +8,7 @@
 
 from typing import TYPE_CHECKING
 
+from . import errors as e
 from .abc import ConnectionType, Params, Query
 from .sql import Composable
 from .rows import Row
@@ -26,6 +27,19 @@
 
 
 class GaussDBRawQuery(GaussDBQuery):
+    """
+    GaussDB raw query class.
+
+    Only supports positional placeholders ($1, $2, ...), not named placeholders.
+    """
+
+    # Query cache size
+    _CACHE_SIZE = 128
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self._query_cache: dict[bytes, bytes] = {}
+
     def convert(self, query: Query, vars: Params | None) -> None:
         if isinstance(query, str):
             bquery = query.encode(self._encoding)
@@ -34,14 +48,43 @@ def convert(self, query: Query, vars: Params | None) -> None:
         else:
             bquery = query
 
-        self.query = bquery
+        # Try to get from cache
+        if bquery in self._query_cache:
+            self.query = self._query_cache[bquery]
+        else:
+            # Validate query doesn't contain named placeholders
+            if b"%(" in bquery:
+                raise e.ProgrammingError(
+                    "RawCursor does not support named placeholders (%(name)s). "
+                    "Use positional placeholders ($1, $2, ...) instead."
+                )
+
+            self.query = bquery
+
+            # Cache result
+            if len(self._query_cache) < self._CACHE_SIZE:
+                self._query_cache[bquery] = bquery
+
         self._want_formats = self._order = None
         self.dump(vars)
 
     def dump(self, vars: Params | None) -> None:
+        """
+        Serialize parameters.
+
+        Args:
+            vars: Parameter sequence (must be sequence, not dict)
+
+        Raises:
+            TypeError: If parameters are not a sequence
+        """
         if vars is not None:
             if not GaussDBQuery.is_params_sequence(vars):
-                raise TypeError("raw queries require a sequence of parameters")
+                raise TypeError(
+                    "RawCursor requires a sequence of parameters (tuple or list), "
+                    f"got {type(vars).__name__}. "
+                    "For named parameters, use regular Cursor instead."
+                )
             self._want_formats = [PyFormat.AUTO] * len(vars)
 
             self.params = self._tx.dump_sequence(vars, self._want_formats)
@@ -52,6 +95,10 @@ def dump(self, vars: Params | None) -> None:
             self.types = ()
             self.formats = None
 
+    def clear_cache(self) -> None:
+        """Clear query cache."""
+        self._query_cache.clear()
+
 
 class RawCursorMixin(BaseCursor[ConnectionType, Row]):
     _query_cls = GaussDBRawQuery

gaussdb/gaussdb/types/array.py

@@ -471,3 +471,23 @@ def _load_binary(data: Buffer, tx: Transformer) -> list[Any]:
         out = [out[i : i + dim] for i in range(0, len(out), dim)]
 
     return out
+
+
+def array_equals_unordered(arr1: list[Any], arr2: list[Any]) -> bool:
+    """
+    Compare two arrays without considering element order.
+
+    Used for GaussDB compatibility scenarios where array element order may differ.
+    """
+    if arr1 is None and arr2 is None:
+        return True
+    if arr1 is None or arr2 is None:
+        return False
+    if len(arr1) != len(arr2):
+        return False
+
+    try:
+        return sorted(arr1) == sorted(arr2)
+    except TypeError:
+        # Elements not sortable, fall back to set comparison
+        return set(map(str, arr1)) == set(map(str, arr2))