从表中扫描多个电子邮件ID-DynamoDB

Question

I'm using @awspilot/dynamodb to fetch data from a customer table where customer_id is the primary key.

I need to get customer id based on multiple customer_email .

dynamodb
    .table('bc_customer')
    .select('customer_id')
    .having('email').eq('test@gmail.com')
    .scan(function( err, data ) {
        console.log(data);
  });

The above code allows me to pass single email id, is there any way to search on multiple email id?

Answer 1

DynamoDB supports query , which allows you to get data from one and only one partition (ie one partition key), or scan which returns every item in the table (ie a full table scan).

If you know the partition keys to query, it will be faster to do multiple queries and combine your result set. If you don't care about performance or you are happy with the speed (bear in mind a scan will scale poorly as your table grows) you can use a scan.

Note that above you are actually doing a scan, and so you are not using your partition key as an index.

A query would be like this:

DynamoDB
    .table('bc_customer')
    .where('email').eq('test@gmail.com')
    .query(function(err, data ) {
        console.log(err,data)
    })

And a scan (I think - the awspilot documents are not too clear) should be something like:

DynamoDB
    .table('bc_customer')
    .having('email').eq('test@gmail.com')
    .having('someattribute').eq('something')
    .scan(function( err, data ) {
        console.log( err, data )
    })