🐛 fix(mcp): 按 schema 校验 PostgreSQL 表存在性

src/dbjavagenix/database/mcp_tools.py

@@ -376,6 +376,10 @@ def get_connection_tools() -> List[Tool]:
                     "table": {
                         "type": "string",
                         "description": "Table name"
+                    },
+                    "schema": {
+                        "type": "string",
+                        "description": "PostgreSQL schema (optional)"
                     }
                 },
                 "required": ["connection_id", "database", "table"]
@@ -867,6 +871,7 @@ async def handle_db_query_table_exists(arguments: Dict[str, Any]) -> List[TextCo
         connection_id = arguments["connection_id"]
         database = arguments["database"]
         table = arguments["table"]
+        schema = arguments.get("schema") or None
 
         # Get connection info to determine database type  
         config = connection_manager.get_connection_info(connection_id)
@@ -883,14 +888,17 @@ async def handle_db_query_table_exists(arguments: Dict[str, Any]) -> List[TextCo
             results = connection_manager.execute_query(connection_id, query, (database, table))
 
         elif config.type == DatabaseType.POSTGRESQL:
+            schema_filter = "AND table_schema = %s" if schema else ""
             query = """
             SELECT COUNT(*) AS count
             FROM information_schema.tables
             WHERE table_catalog = %s
               AND table_name = %s
               AND table_schema NOT IN ('pg_catalog', 'information_schema')
-            """
-            results = connection_manager.execute_query(connection_id, query, (database, table))
+              {schema_filter}
+            """.format(schema_filter=schema_filter)
+            params = (database, table, schema) if schema else (database, table)
+            results = connection_manager.execute_query(connection_id, query, params)
 
         elif config.type == DatabaseType.SQLITE:
             query = """
@@ -906,10 +914,11 @@ async def handle_db_query_table_exists(arguments: Dict[str, Any]) -> List[TextCo
         exists = results[0]["count"] > 0 if results else False
 
         response = {
-            "success": True,
-            "database": database,
-            "table": table,
-            "exists": exists
+            "success": True,
+            "database": database,
+            "table": table,
+            "schema": schema,
+            "exists": exists
         }
 
         status = "exists" if exists else "does not exist"

tests/unit/test_database_capabilities.py

@@ -35,6 +35,18 @@ def test_connection_tool_schema_only_advertises_implemented_databases():
     )
 
 
+def test_table_exists_tool_advertises_optional_postgresql_schema():
+    table_tool = next(
+        tool for tool in get_connection_tools() if tool.name == "db_query_table_exists"
+    )
+
+    assert table_tool.inputSchema["properties"]["schema"] == {
+        "type": "string",
+        "description": "PostgreSQL schema (optional)",
+    }
+    assert "schema" not in table_tool.inputSchema["required"]
+
+
 def test_cli_version_only_advertises_implemented_databases():
     result = CliRunner().invoke(cli.app, ["version"])
 

tests/unit/test_mcp_error_json.py

@@ -114,5 +114,6 @@ async def test_table_exists_success_raw_response_is_json(monkeypatch):
         "success": True,
         "database": "app",
         "table": "users",
+        "schema": None,
         "exists": True,
     }

tests/unit/test_postgresql_mcp_tools.py

@@ -196,6 +196,30 @@ def execute_query(connection_id, query, params=None):
     assert calls[0][2] == ("app", "users")
 
 
+@pytest.mark.asyncio
+async def test_table_exists_applies_postgresql_schema_filter_with_bound_parameter(
+    monkeypatch, postgres_info
+):
+    calls = []
+    monkeypatch.setattr(
+        mcp_tools.connection_manager, "get_connection_info", lambda cid: postgres_info
+    )
+
+    def execute_query(connection_id, query, params=None):
+        calls.append((connection_id, query, params))
+        return [{"count": 1}]
+
+    monkeypatch.setattr(mcp_tools.connection_manager, "execute_query", execute_query)
+
+    response = await mcp_tools.handle_db_query_table_exists(
+        {"connection_id": "pg-1", "database": "app", "table": "users", "schema": "tenant_a"}
+    )
+
+    assert "exists in database" in response[0].text
+    assert "table_schema = %s" in calls[0][1]
+    assert calls[0][2] == ("app", "users", "tenant_a")
+
+
 def test_postgresql_java_mapping_normalizes_catalog_type_names():
     assert mcp_tools._get_java_type_mapping(
         DatabaseType.POSTGRESQL, "timestamp with time zone"