aws_lambda_dynamo_query.js

var doc = require('dynamodb-doc');
var dynamo = new doc.DynamoDB();


function handleResult(context, event){
    return function(){
        var result = this.data || {Count:0, Items:[]};
        var data = {total:result.Count};
        data.items = result.Items.map(function(result){
           return {email:result.Email, tenant:result.Tenant}; 
        });
        context.succeed(data);
    }
}

exports.handler = function(event, context) {
    var tenant = event.tenant;
    
    if(tenant) {
        var params = {
            TableName : "Users",
            KeyConditionExpression: "#ten = :tenant",
            ExpressionAttributeNames:{
                "#ten": 'Tenant'
            },
            ExpressionAttributeValues: {
                ":tenant": tenant
            }
        };
        
        dynamo.query(params, handleResult(context, event));
    } else {
        context.fail('Invalid parameters to find for the user!');
    }
};