====== Dynamo DB CLI examples ======

[[aws:dynamodb-local|Local install of AWS DynamoDB]]
===== List Tables:- =====

<code>
$ aws dynamodb --profile nonprod_admin list-tables
{
    "TableNames": [
        "lifecycle-exceptions", 
        "github_sync"
    ]
}
</code>

<code>
$ aws dynamodb list-tables --profile nonprod_admin | jq .[][] | grep -i 'dev\|test\|nonprod'
"dev-access"
"dev-accounts"
"dev-historic"
"dev-accounts-data"
"ami-builder-dev-account-contacts-data"
"ami-builder-dev-pager-duty-service-data"
"sharedservices-statefiles-nonprod"

</code>

===== Scan table for all items:- =====

<code>
$ aws dynamodb --profile nonprod scan --table-name lifecycle-exceptions
{
    "Count": 2, 
    "Items": [
        {
            "deregister": {
                "S": "no"
            }, 
            "depermission": {
                "S": "yes"
            }, 
            "AMI_image_ID": {
                "S": "ami-0f97eef128d6caaaa"
            }
        }, 
        {
            "deregister": {
                "S": "no"
            }, 
            "depermission": {
                "S": "no"
            }, 
            "AMI_image_ID": {
                "S": "ami-0d99e8b1b672aaaaa"
            }
        }
    ], 
    "ScannedCount": 2, 
    "ConsumedCapacity": null
}

</code>


===== Scan Table with filter =====

Use a filter to return only certain items. Note (from AWS) "A single Scan request can retrieve a maximum of 1 MB of data", I think this is before a filter has been applied. 

<code>
$ aws dynamodb scan --table-name aws-requests-prod-access --filter-expression "createdTimestamp = :time" --expression-attribute-values '{":time":{"S":"1571147906.257259"}}'
1	1255
ACTIONTIMESTAMP	1571148016.286638
ACTIONTYPE	Approved
</code>


<code>
$ aws dynamodb scan --table-name aws-requests-prod-access --filter-expression "createdTimestamp > :time" --expression-attribute-values '{":time":{"S":"1571147906.257259"}}' | more
923     1255
ACTIONTIMESTAMP NULL
ACTIONTYPE      NULL
APPROVER        NULL
AWSACCOUNTID    464365807467
</code>

<code>
$ aws dynamodb scan --table-name aws-requests-prod-access --filter-expression "createdTimestamp > :time" --expression-attribute-values '{":time":{"S":"1571147906.257259"}}' | more
923     1255
ACTIONTIMESTAMP NULL
ACTIONTYPE      NULL
APPROVER        NULL
AWSACCOUNTID    464365807467
CREATEDTIMESTAMP        1572545806.294259
</code>

===== Query for one item:- =====


<code>
$ aws dynamodb get-item --profile nonprod_admin  --table-name lifecycle-exceptions --key '{"AMI_image_ID": {"S": "ami-0d99e8b1b672aaaaa"}}'
{
    "Item": {
        "deregister": {
            "S": "no"
        }, 
        "depermission": {
            "S": "no"
        }, 
        "AMI_image_ID": {
            "S": "ami-0d99e8b1b672aaaaa"
        }
    }
}
</code>



===== Get Item =====

First attempt:-
<code>
$ aws dynamodb get-item --table-name aws-requests-prod-access --key '{"requestid":"9915-01252ca5a755"}'

Parameter validation failed:
Invalid type for parameter Key.requestid, value: 9915-01252ca5a755, type: <class 'str'>, valid types: <class 'dict'>
</code>

So the key type needs to be specified, this can be found from the schema of the database. In my case requestId is the PartitionKey and is set to ''string''.

<code>
$ aws dynamodb get-item --table-name aws-requests-prod-access --key '{"requestid": {"S": "9915-01252ca5a755"} }'

An error occurred (ValidationException) when calling the GetItem operation: The provided key element does not match the schema
</code>

The key is case sensitive, so this worked:-

<code>
$ aws dynamodb get-item --table-name aws-requests-prod-access --key '{"requestId": {"S": "9915-01252ca5a755"} }'
ACTIONTIMESTAMP	1568714628.555759
ACTIONTYPE	Approved
... edited ...
</code>



===== Lambda Function - Boto3 =====

<code python>
import json
import boto3
from datetime import datetime

DDB_TABLE_NAME = 'BrownBag-AccessRequests'

''' test event
{
  "awsAccountId": "12348765",
  "actionType": "NewRequest",
  "status": "Approved"
}
'''

def lambda_handler(event, context):
    print("event is", event)
 
    yearmonth, daytime = get_current_time()
    print("time", yearmonth, 'and', daytime )   
    insertresponse =  insertData(yearmonth,daytime, 
                          event['awsAccountId'], 
                          event['actionType'], 
                          event['status'] 
                          )
 
  
def get_current_time():
    yearmonth = datetime.now().strftime('%Y-%m')
    daytime = datetime.now().strftime('%d-%H:%M:%S')
    return yearmonth, daytime
 
 
def insertData(yearmonth, daytime, account, actiontype, status):
    # cannot use just 'type' as it is a reserved word.
    client = boto3.client('dynamodb')
    response = client.put_item(
        TableName = DDB_TABLE_NAME,
        Item = {
            'year-month':{
                'S': yearmonth,
            },
            'day-time':{
                'S': daytime,
            },
            'Account': {
                'S': account,
            },
            'Type': {
                'S': actiontype,
            },
            'Status': {
                'S': status,
            },
        }
        )
    return response
</code>


===== Scan Table =====


<code python>
#!/usr/bin/env python

import boto3
from datetime import date, time, datetime

dynamodb = boto3.resource('dynamodb', region_name='eu-west-1')
table = dynamodb.Table('aws-requests-prod-access')
#filter = 
print ("dynamodb is", dynamodb)
data = table.scan(
    FilterExpression='createdTimestamp > :time',
    ExpressionAttributeValues={":time":{'S':'1571147906.257259'}}
#AttributeError: 'str' object has no attribute 'update'
)
print (data)



#response = table.scan(
#        FilterExpression=Attr("Date").eq(date) and Attr("Shift").eq(shift)
#    )


#fe = Key('year').between(1950, 1959)
#pe = "#yr, title, info.rating"
# Expression Attribute Names for Projection Expression only.
#ean = { "#yr": "year", }
#esk = None
#response = table.scan(
#    FilterExpression=fe,
#    ProjectionExpression=pe,
#    ExpressionAttributeNames=ean
#    )



#aws dynamodb scan --table-name aws-requests-prod-access --filter-expression "createdTimestamp > :time" --expression-attribute-values '{":time":{"S":"1571147906.257259"}}'
</code>


===== Scan and query table =====

<code>
dynamodb = boto3.resource('dynamodb')
table = dynamodb.Table('MyTable')

# table scan gets all items - caution for large tables!!
scan_response = table.scan()
print("Items", scan_response['Items'], "\n\n")
    
    
# table query for comp key
key_expression = Key('CustomerNumber').eq(custnum) & Key('Id').eq(id)
    
query_response = table.query(
    KeyConditionExpression=key_expression
    )
   
print("query resp, Total:- ", query_response)
print("query resp, Items:- ", query_response['Items'], "item count:- ", query_response['Count'])
</code>