1. Use the aws dynamodb put-item CLI command to add an item to the DynamoDB table:

aws dynamodb put-item 
    --table-name my_table 
    --item '{"id":{"S":"001"}, "datetime":{"N":"1536898265"}, "field1":{"N":"20"}}' 
    --region us-east-1
    --profile admin

2. Add a data item with different sets of attributes:

aws dynamodb put-item 
    --table-name my_table 
    --item '{"id":{"S":"001"},"datetime":{"N":"1536898285"}, "field1":{"N":"30"}, "field2":{"S":"ABC"}}' 
    --region us-east-1
    --profile admin

We added an additional attribute, field2.

3. Add an item with an existing field, but different data type:

aws dynamodb put-item 
    --table-name my_table 
    --item '{"id":{"S":"002"},"datetime":{"N":"1536898295"}, "field1":{"S":"DEF"}}' 
    --region us-east-1
    --profile admin