Creating Amazon DynamoDB Table Items from a JSON File

The following example uses the DynamoDB PutItem operation in a loop to create the items defined in movie_data.json file in the Movies table in your default region.

Create the file DynamoDBLoadItems.go. Add the following statements to import the Go and AWS SDK for Go packages used in the example.

import (
    "github.com/aws/aws-sdk-go/aws"
    "github.com/aws/aws-sdk-go/aws/session"
    "github.com/aws/aws-sdk-go/service/dynamodb"
    "github.com/aws/aws-sdk-go/service/dynamodb/dynamodbattribute"

    "encoding/json"
    "fmt"
    "log"
    "io/ioutil"
    "strconv"
)

Create the data structure we use to contain the information about the table item.

// Create struct to hold info about new item
type Item struct {
    Year   int
    Title  string
    Plot   string
    Rating float64
}

Create a function to get the table items from the JSON file.

// Get table items from JSON file
func getItems() []Item {
    raw, err := ioutil.ReadFile("./.movie_data.json")
    if err != nil {
        log.Fatalf("Got error reading file: %s", err)
    }

    var items []Item
    json.Unmarshal(raw, &items)
    return items
}

Initialize a session that the SDK will use to load credentials from the shared credentials file ~/.aws/credentials and region from the shared configuration file ~/.aws/config and create a new DynamoDB service client.

// Initialize a session that the SDK will use to load
// credentials from the shared credentials file ~/.aws/credentials
// and region from the shared configuration file ~/.aws/config.
sess := session.Must(session.NewSessionWithOptions(session.Options{
    SharedConfigState: session.SharedConfigEnable,
}))

// Create DynamoDB client
svc := dynamodb.New(sess)

Call getItems to get the items. Loop through each item, marshall that data into a map of AttributeValue objects, add the item to the Movies table, and print out the title and year of the movie added to the table.

// Get table items from .movie_data.json
items := getItems()

// Add each item to Movies table:
tableName := "Movies"

for _, item := range items {
    av, err := dynamodbattribute.MarshalMap(item)
    if err != nil {
        log.Fatalf("Got error marshalling map: %s", err)
    }

    // Create item in table Movies
    input := &dynamodb.PutItemInput{
        Item:      av,
        TableName: aws.String(tableName),
    }

    _, err = svc.PutItem(input)
    if err != nil {
        log.Fatalf("Got error calling PutItem: %s", err)
    }

    year := strconv.Itoa(item.Year)

    fmt.Println("Successfully added '" + item.Title + "' (" + year + ") to table " + tableName)

See the complete example and a sample JSON file on GitHub.