fix(dameng): degrade trigger metadata to unavailable on permission errors

agents/drivers/dameng/src/main/java/com/dbx/agent/dameng/DamengAgent.java

@@ -744,6 +744,9 @@ public final class DamengAgent extends AbstractJdbcAgent {
                 if (errorCode == -3325 || errorCode == -2207) {
                     return true;
                 }
+                if (isDamengPermissionError(candidate)) {
+                    return true;
+                }
                 String message = candidate.getMessage();
                 if (message == null) {
                     continue;
@@ -786,6 +789,27 @@ public final class DamengAgent extends AbstractJdbcAgent {
         return false;
     }
 
+    /**
+     * 达梦中文环境在无权限时只返回「权限不足」（vendorCode -5669），消息里不带对象名，
+     * 无法通过 {@link #isDamengMetadataUnavailableError} 的对象名匹配识别。
+     * 这类错误同样应按「元数据不可用」处理：走字典视图降级，而不是让查看对象直接报错。
+     */
+    private static boolean isDamengPermissionError(SQLException error) {
+        if (error.getErrorCode() == -5669) {
+            return true;
+        }
+        String message = error.getMessage();
+        if (message == null) {
+            return false;
+        }
+        String normalized = message.toLowerCase(Locale.ROOT);
+        return normalized.contains("权限")
+            || normalized.contains("privilege")
+            || normalized.contains("permission")
+            || normalized.contains("access denied")
+            || normalized.contains("not authorized");
+    }
+
     /** 连接类错误（断连/超时等）不属于元数据不可用，必须继续上抛。 */
     private static boolean isDamengConnectionError(Throwable error) {
         for (Throwable current = error; current != null; current = current.getCause()) {

agents/drivers/dameng/src/test/java/com/dbx/agent/dameng/DamengAgentMetadataTest.java

@@ -1159,6 +1159,37 @@ class DamengAgentMetadataTest {
         Assertions.assertTrue(source.getSource().contains("系统字典视图"), source.getSource());
     }
 
+    @Test
+    void fallsBackToTriggerCatalogWhenDbmsMetadataPermissionDenied() {
+        DamengAgent agent = new DamengAgent();
+        List<String> sqls = new ArrayList<>();
+        TestSupport.setPrivateConnection(agent, proxy(Connection.class, (method, args) -> {
+            if ("prepareStatement".equals(method.getName())) {
+                String sql = (String) args[0];
+                sqls.add(sql);
+                if (sql.contains("DBMS_METADATA.GET_DDL")) {
+                    return failingMetadataStatement(new SQLException("权限不足", "28000", -5669));
+                }
+                if (sql.contains("ALL_TRIGGERS")) {
+                    return metadataStatement(List.of(List.of("BEGIN NULL; END;")));
+                }
+            }
+            if ("close".equals(method.getName())) {
+                return null;
+            }
+            if ("isClosed".equals(method.getName())) {
+                return false;
+            }
+            return defaultValue(method.getReturnType());
+        }));
+
+        ObjectSource source = agent.getObjectSource("APP", "TRG_AUDIT", "TRIGGER");
+
+        Assertions.assertTrue(source.getSource().contains("BEGIN NULL; END;"), source.getSource());
+        Assertions.assertTrue(source.getSource().contains("系统字典视图"), source.getSource());
+        Assertions.assertTrue(sqls.stream().anyMatch(sql -> sql.contains("ALL_TRIGGERS")), String.join("\n", sqls));
+    }
+
     @Test
     void tableDdlFallsBackToViewAndMaterializedViewCatalogDefinitions() {
         DamengAgent agent = new DamengAgent();