我正在使用杜松子酒和gorpSQL：SELECT p.project_id, p.name, COALESCE(NULLIF(json_agg(a.*)::TEXT, '[null]'), '[]')::JSON AS apps FROM project p LEFT JOIN app a USING (project_id) WHERE p.user_id=19 GROUP BY p.project_id, p.name ORDER BY project_id結(jié)果： 高朗type Project struct {    ID        int64           `db:"project_id, primarykey, autoincrement" json:"id"`    UserID    int64           `db:"user_id" json:"user_id"`    Name      string          `db:"name" json:"name"`    Status    int             `db:"status" json:"status"`    UpdatedAt int64           `db:"updated_at" json:"updated_at"`    CreatedAt int64           `db:"created_at" json:"created_at"`    Apps      json.RawMessage `json:"apps"`}func GetProjects(userID int64, page string) []Project {    var projects []Project    var err error    _, err = db.GetDB().Select(&projects, "SELECT p.project_id, p.name, COALESCE(NULLIF(json_agg(a.*)::TEXT, '[null]'), '[]')::JSON AS apps FROM project p LEFT JOIN app a USING (project_id) WHERE p.user_id=$1 GROUP BY p.project_id, p.name ORDER BY project_id LIMIT 10 OFFSET $2", userID, page)    fmt.Println("err", err)    return projects}并使用以下方法返回結(jié)果： c.JSON(200, gin.H{"data": projects})如果只有一個項目，它會起作用但如果有多個項目，則會出現(xiàn)以下錯誤：錯誤： json: error calling MarshalJSON for type json.RawMessage: invalid character '"' after top-level value有什么建議？PS：我是 Golang 的新手