DynamodbToCSV4j

This application will export the content of a DynamoDB table into a CSV (Comma delimited value) output. All you need to do is create a config.json file in that same directory where you configure your accessKeyId, secretAccessKey and region as such:

{
  "accessKeyId": "REPLACE",
  "secretAccessKey": "REPLACE",
  "region": "eu-west-1",
  "tableName":"testtable"
}

Usage

Command Line

• java DynamodbToCSV4j

This will use the config.json file on your path.

• java DynamodbToCSV4j myConfig.json

This will use the myConfig.json file.

Configuration

Mandatory Configuration settings

parameter	Description
accessKeyId	Your AWS access key
secretAccessKey	Your AWS secret access key
region	The AWS Region name
tableName	The name of the dynamodb table

Optional Configuration settings

parameter	Description
outputfile	The outputfile. Default will be tablename.csv
delimiter	The column delimiter, default will be ,
quotechar	The csv quote character
headers	If set to anything but "true", the column headers will not be in the output
nullstring	String to put in columns that have no value
filterExpression	The filter expression for the scan operation to get the data from dynamodb
expressionAttributeValues	The values for the filterExpression
expressionAttributeNames	The names for the filterExpression

Examples

The examples will use a very simple table, with mixed records that contain maps and lists.

Example 1

Configuration

{
  "accessKeyId": "REPLACE",
  "secretAccessKey": "REPLACE",
  "region": "eu-west-1",
  "tableName":"testtable",
  "outputfile":"example_1.csv",
  "delimiter":";",
  "quotechar":"\"",
  "headers":"true",
  "nullstring":"N/A",
  "filterExpression":"#lastName = :lastName",
  "expressionAttributeValues" : 
		[
			{"name":":lastName", "value":"Steinbeck", "type":"S"}
		],
	"expressionAttributeNames" : 
		[
			{"name":"#lastName", "value":"lastName"}
		]
}

Output

lastName;firstName;books.0;books.1;books.2;secondary_key;primary_key
Steinbeck;John;Of Mice and Man;Travels With Charlie;Tortilla Flat;1;1

Example 2

Configuration

{
  "accessKeyId": "REPLACE",
  "secretAccessKey": "REPLACE",
  "region": "eu-west-1",
  "tableName":"testtable",
  "outputfile":"example_2.csv",
  "delimiter":";",
  "quotechar":"\"",
  "headers":"true",
  "nullstring":"N/A"
}

Output

lastName;firstName;books.0;books.1;books.2;books.3;books.4;secondary_key;Genre.subtype;Genre.type;primary_key
Hamilton;Peter;Pandora's Star;Judas Unchained;The Dreaming Void;The Temportal Void;The Evolutionary Void;2;Space Opera;Science Fiction;2
Steinbeck;John;Of Mice and Man;Travels With Charlie;Tortilla Flat;N/A;N/A;1;N/A;N/A;1

Maven

The project can be used as a Maven dependency by using jitpack.io.

• add the repository :

<repository>
  <id>jitpack.io</id>
  <url>https://jitpack.io</url>
</repository>

• add the dependency

<dependencies>
	<dependency>
	    <groupId>com.github.dhorions</groupId>
	    <artifactId>DynamodbToCSV4j</artifactId>
	    <version>v0.1</version>
	</dependency>
</dependencies>

Usage in your java code

JSONObject config = new JSONObject();
config.put("accessKeyId","REPLACE");
config.put("secretAccessKey","REPLACE");
config.put("region","eu-west-1");
config.put("tableName","testtable");
d2csv d = new d2csv(config);

Alternative options to export data from dynamodb to csv

This article on medium gives an overview of alternative options to export data to comma separated files from dynamodb.