AWS DynamoDB ExclusiveStartKey default value










1















I'm trying to make a query to DynamoDB, and if a LastEvaluatedKey is returned (meaning the query exceeds 1 MB) I want to make other queries in order to fetch all the required data from the table, using LastEvaluatedKey as ExclusiveStartKey for the next query.
This is the code I have for now:



query_response = table.query(
KeyConditionExpression=Key('brand').eq(brand)
)

pagination_key = None

if 'LastEvaluatedKey' in query_response:
pagination_key = query_response['LastEvaluatedKey']

while pagination_key:
next_query_response = table.query(
KeyConditionExpression=Key('brand').eq(brand),
ExclusiveStartKey=pagination_key
)


However, I'd like to refacto this code by extracting the query into a method, passing it pagination_key as an argument. To do this, I'd have to be able to either set ExclusiveStartKey to False, None or some other default value for the first call but I didn't find anything on this, or I'd have to be able to exclude the ExclusiveStartKey alltogether, but I don't know how to do this either.










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  • I know you can simply omit the ExclusiveStartKey or set it to null in the java sdk. Have you tried simply omitting that argument or setting it to None? What were your results?

    – Matthew Pope
    Nov 15 '18 at 16:56















1















I'm trying to make a query to DynamoDB, and if a LastEvaluatedKey is returned (meaning the query exceeds 1 MB) I want to make other queries in order to fetch all the required data from the table, using LastEvaluatedKey as ExclusiveStartKey for the next query.
This is the code I have for now:



query_response = table.query(
KeyConditionExpression=Key('brand').eq(brand)
)

pagination_key = None

if 'LastEvaluatedKey' in query_response:
pagination_key = query_response['LastEvaluatedKey']

while pagination_key:
next_query_response = table.query(
KeyConditionExpression=Key('brand').eq(brand),
ExclusiveStartKey=pagination_key
)


However, I'd like to refacto this code by extracting the query into a method, passing it pagination_key as an argument. To do this, I'd have to be able to either set ExclusiveStartKey to False, None or some other default value for the first call but I didn't find anything on this, or I'd have to be able to exclude the ExclusiveStartKey alltogether, but I don't know how to do this either.










share|improve this question
























  • I know you can simply omit the ExclusiveStartKey or set it to null in the java sdk. Have you tried simply omitting that argument or setting it to None? What were your results?

    – Matthew Pope
    Nov 15 '18 at 16:56













1












1








1








I'm trying to make a query to DynamoDB, and if a LastEvaluatedKey is returned (meaning the query exceeds 1 MB) I want to make other queries in order to fetch all the required data from the table, using LastEvaluatedKey as ExclusiveStartKey for the next query.
This is the code I have for now:



query_response = table.query(
KeyConditionExpression=Key('brand').eq(brand)
)

pagination_key = None

if 'LastEvaluatedKey' in query_response:
pagination_key = query_response['LastEvaluatedKey']

while pagination_key:
next_query_response = table.query(
KeyConditionExpression=Key('brand').eq(brand),
ExclusiveStartKey=pagination_key
)


However, I'd like to refacto this code by extracting the query into a method, passing it pagination_key as an argument. To do this, I'd have to be able to either set ExclusiveStartKey to False, None or some other default value for the first call but I didn't find anything on this, or I'd have to be able to exclude the ExclusiveStartKey alltogether, but I don't know how to do this either.










share|improve this question
















I'm trying to make a query to DynamoDB, and if a LastEvaluatedKey is returned (meaning the query exceeds 1 MB) I want to make other queries in order to fetch all the required data from the table, using LastEvaluatedKey as ExclusiveStartKey for the next query.
This is the code I have for now:



query_response = table.query(
KeyConditionExpression=Key('brand').eq(brand)
)

pagination_key = None

if 'LastEvaluatedKey' in query_response:
pagination_key = query_response['LastEvaluatedKey']

while pagination_key:
next_query_response = table.query(
KeyConditionExpression=Key('brand').eq(brand),
ExclusiveStartKey=pagination_key
)


However, I'd like to refacto this code by extracting the query into a method, passing it pagination_key as an argument. To do this, I'd have to be able to either set ExclusiveStartKey to False, None or some other default value for the first call but I didn't find anything on this, or I'd have to be able to exclude the ExclusiveStartKey alltogether, but I don't know how to do this either.







python amazon-dynamodb






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edited Nov 12 '18 at 14:56









Aqueous Carlos

293213




293213










asked Nov 12 '18 at 14:40









nicojoncknicojonck

334




334












  • I know you can simply omit the ExclusiveStartKey or set it to null in the java sdk. Have you tried simply omitting that argument or setting it to None? What were your results?

    – Matthew Pope
    Nov 15 '18 at 16:56

















  • I know you can simply omit the ExclusiveStartKey or set it to null in the java sdk. Have you tried simply omitting that argument or setting it to None? What were your results?

    – Matthew Pope
    Nov 15 '18 at 16:56
















I know you can simply omit the ExclusiveStartKey or set it to null in the java sdk. Have you tried simply omitting that argument or setting it to None? What were your results?

– Matthew Pope
Nov 15 '18 at 16:56





I know you can simply omit the ExclusiveStartKey or set it to null in the java sdk. Have you tried simply omitting that argument or setting it to None? What were your results?

– Matthew Pope
Nov 15 '18 at 16:56












1 Answer
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active

oldest

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0














I found an easy way of building the parameters:




query_params = 'KeyConditionExpression': Key('brand').eq(brand) 

if pagination_key:
query_params['ExclusiveStartKey'] = pagination_key

query_response = table.query(query_params)






share|improve this answer






















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    1 Answer
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    active

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    0














    I found an easy way of building the parameters:




    query_params = 'KeyConditionExpression': Key('brand').eq(brand) 

    if pagination_key:
    query_params['ExclusiveStartKey'] = pagination_key

    query_response = table.query(query_params)






    share|improve this answer



























      0














      I found an easy way of building the parameters:




      query_params = 'KeyConditionExpression': Key('brand').eq(brand) 

      if pagination_key:
      query_params['ExclusiveStartKey'] = pagination_key

      query_response = table.query(query_params)






      share|improve this answer

























        0












        0








        0







        I found an easy way of building the parameters:




        query_params = 'KeyConditionExpression': Key('brand').eq(brand) 

        if pagination_key:
        query_params['ExclusiveStartKey'] = pagination_key

        query_response = table.query(query_params)






        share|improve this answer













        I found an easy way of building the parameters:




        query_params = 'KeyConditionExpression': Key('brand').eq(brand) 

        if pagination_key:
        query_params['ExclusiveStartKey'] = pagination_key

        query_response = table.query(query_params)







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Dec 7 '18 at 11:26









        nicojoncknicojonck

        334




        334



























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