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Search Results for: Dynamo

AWS Lambda/Java, DynamoDB and Api gateway integration

Introduction In this post I am going through a full (Java) example of integrating AWS Lambda, DynamoDb and Api Gateway to create a function and expose this function as a HTTP resource for other parties to consume. Before we dive into the details I will give a brief overview of the AWS services used in this example (as taken from ...

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Scan DynamoDB Items with DynamoDBMapper

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Previously we covered how to query a DynamoDB database either using DynamoDBMapper or the low level java api. Apart from issuing queries, DynamoDB also offers Scan functionality. What scan does, is fetching all the Items you might have on your DynamoDB Table. Therefore scan does not require any rules based on our partition key or your global/local secondary indexes. What ...

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Query DynamoDB Items with DynamoDBMapper

java-interview-questions-answers

On a previous post we issued queries on a DynamoDB database using the low level java api. Querying using the DynamoDBMapper is pretty easy. Issue a query using a hash key is as simple as it gets. The best candidate for a query like this would be the Users table by searching using the email hash key. public User getUser(String ...

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Insert DynamoDB Items with DynamoDBMapper

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In a previous post we used DynamoDBMapper in order to map DynamoDB Tables into Java objects. When it comes to insert, our actions are pretty much the same but with a more convenient way. In order to insert an item all you have to do is to persist an object using the object mapper In our case, we will create ...

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Map DynamoDB Items to Objects using DynamoDB mapper

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Previously we created DynamoDB Tables using Java. For various databases such sql databases or nosql there is a set of tools that help to access, persist, and manage data between objects/classes and the underlying database. For example for SQL databases we use JPA, for Cassandra we use MappingManager. DynamoDBMapper is a tool that enables you to access your data in ...

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Update DynamoDB Items with Java

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On a previous post we proceeded into inserting items to DynamoDB using Java. DynamoDB also supports updating items. We will use the Login table for the update examples. When issuing an update you must specify the primary key of the item you want to update. public void updateName(String email,String fullName) { Map<String,AttributeValue> attributeValues = new HashMap<>(); attributeValues.put("email",new AttributeValue().withS(email)); attributeValues.put("fullname",new AttributeValue().withS(fullName)); ...

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Scan DynamoDB Items with Java

java-interview-questions-answers

On previous posts we covered how to query a DynamoDB database Query DynamoDB Part 1 Query DynamoDB Part2. Apart from issuing queries DynamoDB also offers Scan functionality. What scan does is fetching all the Items you might have on your DynamoDB Table. Therefore scan does not require any rules based on our partition key or your global/local secondary indexes. What scan offers is ...

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Query DynamoDB Items with Java Part 2

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On a previous post we had the chance to issue some basic DynamoDB query actions. However apart from the basic actions the DynamoDB api provides us with some extra functionality. Projections is a feature that has a select-like functionality. You choose which attributes from a DynamoDB Item shall be fetched. Keep in mind that using projection will not have any ...

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Query DynamoDB Items with Java

On a previous post we proceeded on inserting data on a DynamoDB database. On this tutorial we will issue some basic queries against our DynamoDB tables. The main rule is that every query has to use the hash key. The simplest form of query is using the hash key only. We will query the Users table on this one. There ...

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