🐛 fix(kingbase): 修复无模式前缀查询失败

- 缓存连接初始化时探测出的 search_path
- 新建固定会话后先同步 schema 搜索路径
- 补充金仓会话初始化顺序回归测试

internal/db/optional_driver_agent_impl.go

@@ -420,8 +420,9 @@ func (c *optionalDriverAgentClient) close() error {
 }
 
 type OptionalDriverAgentDB struct {
-	driverType string
-	client     *optionalDriverAgentClient
+	driverType         string
+	client             *optionalDriverAgentClient
+	kingbaseSearchPath string
 }
 
 type optionalDriverAgentTransactionalDB struct {
@@ -462,6 +463,7 @@ func newOptionalDriverAgentTransactionalDatabase(driverType string) databaseFact
 }
 
 func (d *OptionalDriverAgentDB) Connect(config connection.ConnectionConfig) error {
+	d.kingbaseSearchPath = ""
 	if d.client != nil {
 		_ = d.client.close()
 		d.client = nil
@@ -692,11 +694,18 @@ func (d *OptionalDriverAgentDB) OpenSessionExecer(ctx context.Context) (Statemen
 	if sessionID == "" {
 		return nil, fmt.Errorf("%s 驱动代理未返回事务会话 ID", driverDisplayName(d.driverType))
 	}
-	return &optionalDriverAgentSession{
+	session := &optionalDriverAgentSession{
 		client:    client,
 		driver:    d.driverType,
 		sessionID: sessionID,
-	}, nil
+	}
+	if searchPath := strings.TrimSpace(d.kingbaseSearchPath); searchPath != "" {
+		if _, err := session.ExecContext(ctx, fmt.Sprintf("SET search_path TO %s", searchPath)); err != nil {
+			_ = session.Close()
+			return nil, fmt.Errorf("人大金仓会话初始化 search_path 失败：%w", err)
+		}
+	}
+	return session, nil
 }
 
 func (d *optionalDriverAgentTransactionalDB) OpenTransactionExecer(ctx context.Context) (TransactionExecer, error) {
@@ -1086,6 +1095,7 @@ func (d *OptionalDriverAgentDB) ensureKingbaseSearchPath(config connection.Conne
 	if strings.TrimSpace(searchPath) == "" {
 		return
 	}
+	d.kingbaseSearchPath = searchPath
 
 	if _, err := d.ExecContext(ctx, fmt.Sprintf("SET search_path TO %s", searchPath)); err != nil {
 		logger.Warnf("人大金仓驱动代理设置 search_path 失败：%v", err)

internal/db/optional_driver_agent_impl_test.go

@@ -244,6 +244,44 @@ func TestOptionalDriverAgentDBQueryMultiWithMessagesParsesResultSets(t *testing.
 	}
 }
 
+func TestKingbaseOptionalDriverAgentSessionInitializesSearchPath(t *testing.T) {
+	var stdin optionalAgentTestWriteCloser
+	stdout := strings.Join([]string{
+		`{"id":1,"success":true,"data":"session-1"}`,
+		`{"id":2,"success":true,"rowsAffected":0}`,
+		`{"id":3,"success":true}`,
+	}, "\n") + "\n"
+
+	dbInst := &OptionalDriverAgentDB{
+		driverType:         "kingbase",
+		kingbaseSearchPath: `"$user",public,ldf_server`,
+		client: &optionalDriverAgentClient{
+			stdin:  &stdin,
+			reader: bufio.NewReader(strings.NewReader(stdout)),
+			driver: "kingbase",
+		},
+	}
+
+	session, err := dbInst.OpenSessionExecer(context.Background())
+	if err != nil {
+		t.Fatalf("OpenSessionExecer returned error: %v", err)
+	}
+	if err := session.Close(); err != nil {
+		t.Fatalf("Close returned error: %v", err)
+	}
+
+	requests := stdin.String()
+	for _, fragment := range []string{
+		`"method":"openSession"`,
+		`"method":"exec","sessionId":"session-1","query":"SET search_path TO \"$user\",public,ldf_server"`,
+		`"method":"closeSession","sessionId":"session-1"`,
+	} {
+		if !strings.Contains(requests, fragment) {
+			t.Fatalf("expected request fragment %q, got %s", fragment, requests)
+		}
+	}
+}
+
 func TestDamengOptionalDriverAgentSupportsManagedTransactions(t *testing.T) {
 	damengDB, err := NewDatabase("dameng")
 	if err != nil {