go - 如何将 JSON 解码为 dynamodb.AttributeValue？

Question

例如，在输入时:

[
        {
            "M": {
                "Capacity": {
                    "S": "7"
                },
                "Energy": {
                    "S": "A+"
                }
            }
        },
        {
            "M": {
                "Capacity": {
                    "S": "7"
                },
                "Energy": {
                    "S": "A++"
                }
            }
        },
        {
            "M": {
                "Capacity": {
                    "S": "7"
                },
                "Energy": {
                    "S": "A+++"
                }
            }
        }
    ]

而不是 Capacity , Energy我可以得到其他 key 。我没有找到任何方法可以从此类输入中进行准备 dynamodb.AttributeValue适用于UpdateItem .

我试图解码为 []map[string]interface{}然后转换为 dynamodb.AttributeValue .

Answer 1

解码到 []map[string]map[string]*dynamodb.AttributeValue{}然后 Capacity和 Energy key 解码为 dynamodb.AttributeValue .

因此，您可以使用 map[string]*dynamodb.AttributeValue 类型的外部映射值如ExpressionAttributeValues在 UpdateItemInput至UpdateItem

package main

import (
    "encoding/json"
    "fmt"

    "github.com/aws/aws-sdk-go/service/dynamodb"
)
func main() {
    data := []byte(`[
        {
            "M": {
                "Capacity": {
                    "S": "7"
                },
                "Energy": {
                    "S": "A+"
                }
            }
        },
        {
            "M": {
                "Capacity": {
                    "S": "7"
                },
                "Energy": {
                    "S": "A++"
                }
            }
        },
        {
            "M": {
                "Capacity": {
                    "S": "7"
                },
                "Energy": {
                    "S": "A+++"
                }
            }
        }
    ]`)

    d := []map[string]map[string]*dynamodb.AttributeValue{}
    json.Unmarshal(data, &d)
    for _, mp := range d {
        expressionAttributeValues := mp["M"]
        // you can use expressionAttributeValues as ExpressionAttributeValues in UpdateItemInput to UpdateItem
        capacity := expressionAttributeValues["Capacity"]
        energy := expressionAttributeValues["Energy"]
        fmt.Printf("%+v", capacity)
        fmt.Printf("%+v", energy)
    }
}