🐛 fix(tdengine): 修复查询结果仅显示执行日志

- TDengine 只读查询跳过不支持的多结果集探测
- 保证可选驱动代理通过普通查询返回完整行列数据
- 补充应用层与驱动层回归测试

Fixes #610

internal/app/methods_db.go

@@ -1700,6 +1700,11 @@ func shouldPreferPlainReadQueryResult(dbType string) bool {
 		"gaussdb", "gauss_db", "gauss-db",
 		"dameng", "dm", "dm8":
 		return true
+	case "tdengine":
+		// TDengine only implements the plain query API. The optional driver-agent
+		// exposes a transport-level multi-result method, but reports it unsupported.
+		// Skipping that probe prevents a successful SELECT from becoming an empty result.
+		return true
 	default:
 		return false
 	}

internal/app/methods_db_sqlite_agent_regression_test.go

@@ -99,7 +99,7 @@ func (s *fakeUnsupportedMultiResultSession) QueryMultiContextWithMessages(contex
 	return nil, nil, nil
 }
 
-func installFakeOptionalSQLiteDatabase(t *testing.T, fakeDB db.Database) {
+func installFakeOptionalDriverDatabase(t *testing.T, fakeDB db.Database) {
 	t.Helper()
 	originalNewDatabaseFunc := newDatabaseFunc
 	originalDriverRuntimeSupportStatusFunc := driverRuntimeSupportStatusFunc
@@ -126,7 +126,7 @@ func TestDBQueryMultiSQLiteAgentStyleQueryReturnsRowsAndAuditCount(t *testing.T)
 		queryErr: map[string]error{},
 	}
 	fakeDB := &fakeUnsupportedMultiResultDB{fakeBatchWriteDB: baseDB}
-	installFakeOptionalSQLiteDatabase(t, fakeDB)
+	installFakeOptionalDriverDatabase(t, fakeDB)
 
 	app := newSQLAuditTestApp(t)
 	config := connection.ConnectionConfig{Type: "sqlite", Host: "/tmp/orders.sqlite"}

internal/app/methods_db_tdengine_agent_regression_test.go

@@ -0,0 +1,64 @@
+package app
+
+import (
+	"context"
+	"errors"
+	"reflect"
+	"testing"
+
+	"GoNavi-Wails/internal/connection"
+	"GoNavi-Wails/internal/db"
+)
+
+type fakeTDengineOptionalAgentDB struct {
+	*fakeUnsupportedMultiResultDB
+}
+
+func (*fakeTDengineOptionalAgentDB) OpenSessionExecer(context.Context) (db.StatementExecer, error) {
+	return nil, errors.New("TDengine driver does not support pinned sessions")
+}
+
+func TestDBQueryMultiTDengineAgentSelectUsesPlainQuery(t *testing.T) {
+	query := "SELECT ts, current FROM meters ORDER BY ts DESC LIMIT 1"
+	baseDB := &fakeBatchWriteDB{
+		queryMap: map[string][]map[string]interface{}{
+			query: {{"ts": "2026-07-19T00:00:00+08:00", "current": 10.2}},
+		},
+		fieldMap: map[string][]string{
+			query: {"ts", "current"},
+		},
+		queryErr: map[string]error{},
+	}
+	fakeDB := &fakeTDengineOptionalAgentDB{
+		fakeUnsupportedMultiResultDB: &fakeUnsupportedMultiResultDB{fakeBatchWriteDB: baseDB},
+	}
+	installFakeOptionalDriverDatabase(t, fakeDB)
+
+	app := NewApp()
+	result := app.DBQueryMulti(
+		connection.ConnectionConfig{Type: "tdengine", Host: "127.0.0.1", Port: 6041},
+		"power",
+		query,
+		"tdengine-agent-select",
+	)
+	if !result.Success {
+		t.Fatalf("TDengine agent SELECT returned failure: %s", result.Message)
+	}
+
+	resultSets, ok := result.Data.([]connection.ResultSetData)
+	if !ok || len(resultSets) != 1 {
+		t.Fatalf("TDengine agent SELECT result sets = %#v, want one result set", result.Data)
+	}
+	if !reflect.DeepEqual(resultSets[0].Columns, []string{"ts", "current"}) {
+		t.Fatalf("TDengine agent SELECT columns = %#v", resultSets[0].Columns)
+	}
+	if len(resultSets[0].Rows) != 1 || resultSets[0].Rows[0]["current"] != 10.2 {
+		t.Fatalf("TDengine agent SELECT rows = %#v, want one data row", resultSets[0].Rows)
+	}
+	if fakeDB.multiCalls != 0 {
+		t.Fatalf("TDengine SELECT must not probe unsupported multi-result API, calls=%d", fakeDB.multiCalls)
+	}
+	if baseDB.queryCalls != 1 {
+		t.Fatalf("TDengine SELECT should execute exactly once through plain Query, calls=%d", baseDB.queryCalls)
+	}
+}