Using JOIN query in AWS DynamoDB using PHP

Question

I am currently using MySQL as database for my application in PHP. But now need to migrate to AWS DynamoDB. As I am new to DynamoDB, can anyone help me using JOIN in DynamoDB?

As per my finding, I have found that, JOINs can be used using Hive and Amazon EMR. But here also there is a problem that no resource is available for using Hive with PHP.

Answer 1

hi maybe you can try this

To join two DynamoDB tables The join is computed on the cluster and returned. The join does not take place in DynamoDB. This example returns a list of customers and their purchases for customers that have placed more than two orders.

CREATE EXTERNAL TABLE hive_purchases(customerId bigint, total_cost double, items_purchased array<String>) 
STORED BY 'org.apache.hadoop.hive.dynamodb.DynamoDBStorageHandler'
TBLPROPERTIES ("dynamodb.table.name" = "Purchases",
"dynamodb.column.mapping" = "customerId:CustomerId,total_cost:Cost,items_purchased:Items");

CREATE EXTERNAL TABLE hive_customers(customerId bigint, customerName string, customerAddress array<String>) 
STORED BY 'org.apache.hadoop.hive.dynamodb.DynamoDBStorageHandler'
TBLPROPERTIES ("dynamodb.table.name" = "Customers",
"dynamodb.column.mapping" = "customerId:CustomerId,customerName:Name,customerAddress:Address");

Select c.customerId, c.customerName, count(*) as count from hive_customers c 
JOIN hive_purchases p ON c.customerId=p.customerId 
GROUP BY c.customerId, c.customerName HAVING count > 2;

To join two tables from different sources

In the following example, Customer_S3 is a Hive table that loads a CSV file stored in Amazon S3 and hive_purchases is a table that references data in DynamoDB. The following example joins together customer data stored as a CSV file in Amazon S3 with order data stored in DynamoDB to return a set of data that represents orders placed by customers who have "Miller" in their name.

CREATE EXTERNAL TABLE hive_purchases(customerId bigint, total_cost double, items_purchased array) STORED BY 'org.apache.hadoop.hive.dynamodb.DynamoDBStorageHandler' TBLPROPERTIES ("dynamodb.table.name" = "Purchases", "dynamodb.column.mapping" = "customerId:CustomerId,total_cost:Cost,items_purchased:Items");

CREATE EXTERNAL TABLE Customer_S3(customerId bigint, customerName string, customerAddress array<String>)
ROW FORMAT DELIMITED FIELDS TERMINATED BY ',' 
LOCATION 's3://bucketname/path/subpath/';

Select c.customerId, c.customerName, c.customerAddress from 
Customer_S3 c 
JOIN hive_purchases p 
ON c.customerid=p.customerid 
where c.customerName like '%Miller%';

for more information you can read the documentation DynamoDB Export , Import Querys

good luck and try

Answer 2

well, migrating sql to NoSQL is a hard decision, you might want to take a look of this white page to see if your application can survive in the NoSQL world.