有一个数组对象，它是从 mongodb 中检索到的。数据如下所示:-

[{
  1 
  fruits 
  Apple 
  Apple is my favorite fruit.
 }
 {
  2 
  colors 
  Red 
  Red color is always charming.
 } 
 {
  3 
  flowers 
  Lotus 
  It is one of the most beautiful flowers in this world.
 }]

这是获取上述数据的代码 结构是:

type Item struct {
  Id          int    `json:"id"`
  Category    string `json:"category"`
  Name        string `json:"name"`
  Description string `json:"description"`
}
type Items []Item

func GetData(Query interface{}) (result Items, err error) {
    mongoSession := ConnectDb()
    sessionCopy := mongoSession.Copy()
    defer sessionCopy.Close()
    getCollection := mongoSession.DB("custom").C("custom")
    err = getCollection.Find(Query).All(&result)
    if err != nil {
        return result, err
    }
    return result, nil
}
/*
 *  Retrieve the data used by main function
 */
func retrieve(c *gin.Context) {
  //mongoSession := ConnectDb()
  conditions := bson.M{}
  data, err :=GetData(conditions)
  if err != nil {
    fmt.Println("There is somthing wrong")
  }
  arrange(data)
  return
}

func arrange(data Items) {
  pagesJson, err := json.Marshal(data)
  if err != nil {
    log.Fatal("Cannot encode to JSON ", err)
  }
  fmt.Println(string(pagesJson))
}

运行 json.Marshal，输出如下所示:

[{
  "id":1,
  "category":"fruits",
  "name":"Apple",
  "description":"Apple is my favorite fruit."
},
{
  "id":2,
  "category":"colors",
  "name":"Red",
  "description":"Red color is always charming."
},
{
  "id":3,
  "category":"flowers",
  "name":"Lotus",
  "description":"It is one of the most beautiful flowers in this world."
}]

预期输出

{
  "id":1,
  "category":"fruits",
  "name":"Apple",
  "description":"Apple is my favorite fruit."
}
{
  "id":2,
  "category":"colors",
  "name":"Red",
  "description":"Red color is always charming."
}
{
  "id":3,
  "category":"flowers",
  "name":"Lotus",
  "description":"It is one of the most beautiful flowers in this world."
}

问题是数据在数组对象中供我使用，我需要 {} 之间的字符串结构数据，如上所示。我之前发布过这个问题，但没有得到任何成功的答案。我一直在尝试帮助我，谢谢。

最佳答案

根据 OP 所讨论的内容，编码结构 Items 会给出:

[{
  "id":1,
  "category":"fruits",
  "name":"Apple",
  "description":"Apple is my favorite fruit."
},
{
  "id":2,
  "category":"colors",
  "name":"Red",
  "description":"Red color is always charming."
},
{
  "id":3,
  "category":"flowers",
  "name":"Lotus",
  "description":"It is one of the most beautiful flowers in this world."
}]

从这里，OP 想要得到一个如下所示的字符串:

{
  "id":1,
  "category":"fruits",
  "name":"Apple",
  "description":"Apple is my favorite fruit."
},
{
  "id":2,
  "category":"colors",
  "name":"Red",
  "description":"Red color is always charming."
},
{
  "id":3,
  "category":"flowers",
  "name":"Lotus",
  "description":"It is one of the most beautiful flowers in this world."
}

我考虑了两种方法:

1. 遍历项目并将每个编码的项目附加到一个字符串中(显然效率不高)

   func getMyString(items Items) (string, error) {
   
       var buffer bytes.Buffer
       var err error
       var b []byte
   
       for _, item := range items {
           b, err = json.Marshal(item)
           if err != nil {
               return "", err
           }
   
           buffer.WriteString(string(b) + ",")
       }
   
       s := strings.TrimSpace(buffer.String())
       // trim last comma
       s = s[:len(s)-1]
   
       return s, nil
   }
   

2. 或者只是去掉前导和尾随的方括号:

   func getMyString2(items Items) (string, error) {
   
       b, err := json.Marshal(items)
       if err != nil {
           return "", err
       }
   
       s := string(b)
       s = strings.TrimSpace(s)
       // trim leading and trailing spaces
       s = s[1 : len(s)-1]
       return s, nil
   }
   

代码链接:https://play.golang.org/p/F1SUYJZEn_n

编辑:由于 OP 希望它以空格分隔，我修改了方法 1 以满足要求:

func getMyString(items Items) (string, error) {
    var buffer bytes.Buffer
    var err error
    var b []byte

    for _, item := range items {
        b, err = json.Marshal(item)
        if err != nil {
            return "", err
        }
        // use space to separate each json string in the array
        buffer.WriteString(string(b) + " ")
    }

    s := strings.TrimSpace(buffer.String())

    return s, nil
}

新代码链接:https://play.golang.org/p/dVvsQlsRqZO

关于mongodb - 如何使用golang将数组对象数据转换为字符串格式数据？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/49685192/