解组 bson.D 对象 (Golang)
Unmarshalling a bson.D object (Golang)
我会尽量说清楚。我正在使用 MongoDB 和 Model-Vew-Controller 架构构建一个简单的审计日志记录 API。作为功能的一部分,用户可以使用 http 端点请求数据。当命中端点时,控制器包调用模型包,并执行以下代码:
// The GetResourceData function takes the resource, and provides the log data for that resource, sorted by // date and time. It also takes a context.context, and a *mongo.Client as parameters.
func GetResourceData(ctx context.Context, CL *mongo.Client, Resource string) error { ourDatabase := CL.Database("Event_Database") eventsCollection := ourDatabase.Collection("Events")
opts := options.Find()
opts.SetSort(bson.D{{"Date", -1}, {"Time", -1}})
filterCursor, err := eventsCollection.Find(
ctx,
bson.M{"Resource": Resource},
opts)
if err != nil {
log.Fatal(err)
}
defer filterCursor.Close(ctx)
for filterCursor.Next(ctx) {
var eventsFiltered []bson.D
if err = filterCursor.All(ctx, &eventsFiltered); err != nil {
log.Fatal(err)
}
fmt.Println(eventsFiltered)
}
return err
}
效果很好,如您所见,我已将 eventsFiltered 打印到终端。然而,它在那里并没有多大用处,我需要将它打印到屏幕上。我有一个函数可以在带有 http.ResponseWriter 的视图包中执行此操作,但是 - 我无法弄清楚如何将 bson.D 转换为字符串格式,因此我可以将其作为参数干净地传递.如果我尝试 bson.Unmarshall;
var cookie []byte
bson.Unmarshal(cookie, eventsFiltered)
s := string(cookie)
fmt.Println("Events filtered as a string is: ", s)
fmt.Println("Events filtered as a byte slice is: ", cookie)
我得到以下信息;
过滤为字符串的用户是:
作为字节片过滤的用户是:[]
...空字符串或空字节片。我知道我缺少一些非常简单的东西,但我看不到它!
如有任何帮助,我们将不胜感激。有问题请追问
谢谢,
A
首先,如果您使用 filterCursor.All(ctx, &eventsFiltered)
,则不需要遍历所有集合或关闭游标(游标方法 All(...)
会为您完成)。
关于你的问题,你可以这样操作:
var eventsFiltered []bson.D
if err = filterCursor.All(ctx, &eventsFiltered); err != nil {
log.Fatal(err)
}
for _, event := range eventsFiltered {
for _, keyValPair := range event {
fmt.Printf("key is %s; val is %v", keyValPair.Key, keyValPair.Value)
}
}
或者,如果元素的顺序无关紧要,请考虑解组为 bson.M
:
var eventsFiltered []bson.M
if err = filterCursor.All(ctx, &eventsFiltered); err != nil {
log.Fatal(err)
}
for _, event := range eventsFiltered {
for key, val := range event {
fmt.Printf("key is %s; val is %v", key, val)
}
}
所以,整个解决方案是:
func GetResourceData(ctx context.Context, CL *mongo.Client, Resource string) error {
ourDatabase := CL.Database("Event_Database")
eventsCollection := ourDatabase.Collection("Events")
opts := options.Find()
opts.SetSort(bson.D{{"Date", -1}, {"Time", -1}})
filterCursor, err := eventsCollection.Find(
ctx,
bson.M{"Resource": Resource},
opts)
if err != nil {
log.Fatal(err)
}
if filterCursor.Next(ctx) {
var eventsFiltered []bson.M
if err = filterCursor.All(ctx, &eventsFiltered); err != nil {
log.Fatal(err)
}
// If you need ordered print, uncomment the following lines and comment out following uncommented for loop
// for _, event := range eventsFiltered {
// for _, keyValPair := range event{
// fmt.Printf("key is %s; val is %v", keyValPair.Key, keyValPair.Value)
// }
// }
for _, event := range eventsFiltered {
for key, val := range event {
fmt.Printf("key is %s; val is %v", key, val)
}
}
}
return nil
}
我会尽量说清楚。我正在使用 MongoDB 和 Model-Vew-Controller 架构构建一个简单的审计日志记录 API。作为功能的一部分,用户可以使用 http 端点请求数据。当命中端点时,控制器包调用模型包,并执行以下代码:
// The GetResourceData function takes the resource, and provides the log data for that resource, sorted by // date and time. It also takes a context.context, and a *mongo.Client as parameters.
func GetResourceData(ctx context.Context, CL *mongo.Client, Resource string) error { ourDatabase := CL.Database("Event_Database") eventsCollection := ourDatabase.Collection("Events")
opts := options.Find()
opts.SetSort(bson.D{{"Date", -1}, {"Time", -1}})
filterCursor, err := eventsCollection.Find(
ctx,
bson.M{"Resource": Resource},
opts)
if err != nil {
log.Fatal(err)
}
defer filterCursor.Close(ctx)
for filterCursor.Next(ctx) {
var eventsFiltered []bson.D
if err = filterCursor.All(ctx, &eventsFiltered); err != nil {
log.Fatal(err)
}
fmt.Println(eventsFiltered)
}
return err
}
效果很好,如您所见,我已将 eventsFiltered 打印到终端。然而,它在那里并没有多大用处,我需要将它打印到屏幕上。我有一个函数可以在带有 http.ResponseWriter 的视图包中执行此操作,但是 - 我无法弄清楚如何将 bson.D 转换为字符串格式,因此我可以将其作为参数干净地传递.如果我尝试 bson.Unmarshall;
var cookie []byte
bson.Unmarshal(cookie, eventsFiltered)
s := string(cookie)
fmt.Println("Events filtered as a string is: ", s)
fmt.Println("Events filtered as a byte slice is: ", cookie)
我得到以下信息;
过滤为字符串的用户是:
作为字节片过滤的用户是:[]
...空字符串或空字节片。我知道我缺少一些非常简单的东西,但我看不到它!
如有任何帮助,我们将不胜感激。有问题请追问
谢谢, A
首先,如果您使用 filterCursor.All(ctx, &eventsFiltered)
,则不需要遍历所有集合或关闭游标(游标方法 All(...)
会为您完成)。
关于你的问题,你可以这样操作:
var eventsFiltered []bson.D
if err = filterCursor.All(ctx, &eventsFiltered); err != nil {
log.Fatal(err)
}
for _, event := range eventsFiltered {
for _, keyValPair := range event {
fmt.Printf("key is %s; val is %v", keyValPair.Key, keyValPair.Value)
}
}
或者,如果元素的顺序无关紧要,请考虑解组为 bson.M
:
var eventsFiltered []bson.M
if err = filterCursor.All(ctx, &eventsFiltered); err != nil {
log.Fatal(err)
}
for _, event := range eventsFiltered {
for key, val := range event {
fmt.Printf("key is %s; val is %v", key, val)
}
}
所以,整个解决方案是:
func GetResourceData(ctx context.Context, CL *mongo.Client, Resource string) error {
ourDatabase := CL.Database("Event_Database")
eventsCollection := ourDatabase.Collection("Events")
opts := options.Find()
opts.SetSort(bson.D{{"Date", -1}, {"Time", -1}})
filterCursor, err := eventsCollection.Find(
ctx,
bson.M{"Resource": Resource},
opts)
if err != nil {
log.Fatal(err)
}
if filterCursor.Next(ctx) {
var eventsFiltered []bson.M
if err = filterCursor.All(ctx, &eventsFiltered); err != nil {
log.Fatal(err)
}
// If you need ordered print, uncomment the following lines and comment out following uncommented for loop
// for _, event := range eventsFiltered {
// for _, keyValPair := range event{
// fmt.Printf("key is %s; val is %v", keyValPair.Key, keyValPair.Value)
// }
// }
for _, event := range eventsFiltered {
for key, val := range event {
fmt.Printf("key is %s; val is %v", key, val)
}
}
}
return nil
}