How do you switch from SQL to Table Storage in Azure Mobile Services? - ios

Question

I've signed up for the free month trial of Azure, and I have created a Mobile Service. I'm using iOS, so I downloaded the model Todo app for iOS.
I am now trying to use Table Storage in the back end instead of a MSSQL store; I have found instructions on using Table Storage here: http://azure.microsoft.com/en-us/documentation/articles/storage-nodejs-how-to-use-table-storage/
However, my app is still storing todo items in the MSSQL storage. I've been told that I don't need to do anything in the client to make the switch, so I assume everything I need to do must be done in the node.js scripts. But I'm clearly missing something.
One thing that confuses me is that after I downloaded the generated node.js script for the Todo app, I didn't see anything in it that seemed to be explicitly talking to the MSSQL database.
Any pointers would be greatly appreciated.
EDIT:
here's my todoitem.insert.js:
var azure = require('azure-storage');
var tableSvc = azure.createTableService();
function insert(item, user, request) {
// request.execute();
console.log('Request received');
console.log(request);
var entGen = azure.TableUtilities.entityGenerator;
var task = {
PartitionKey: entGen.String('learningazure'),
RowKey: entGen.String('1'),
description: entGen.String('add something to TS'),
dueDate: entGen.DateTime(new Date(Date.UTC(2014, 11, 5))),
};
tableSvc.insertEntity('codedelphi',task, {echoContent: true}, function (error, result, response) {
if(!error){
// Entity inserted
console.log('No error on table insert: task created.');
request.respond(statusCodes.SUCCESS, 'OK.');
} else {
console.log('Houston, we have a problem. Entity not added to table.');
console.log(error);
}
});
console.log(JSON.stringify(item, null, 4));
}
tableSvc.createTableIfNotExists('codedelphi', function(error, result, response){
if(!error){
// Table exists or created
console.log('No error, table should exist');
} else {
console.log('We have a problem.');
console.log(error);
}
});

Answer 1

Mobile Services has the built in capability to handle talking to your SQL Database for you. When your script calls "request.execute()" that triggers whatever the request is (insert, update, delete, select) to be ran against the SQL database. Talking to Table Storage instead of SQL requires you to edit those scripts to explicitly talk to Table Storage (i.e. perform your insert, update, deletes, and reads). Today there is no magic switch which will change your "request.execute" from talking to SQL to talk to Table Storage. If you've already edited your scripts to talk to Table Storage and it's not working / you still see data stored in your SQL database, I would suspect that you are either still calling "request.execute" in your scripts, or you haven't pushed them to your Mobile Service (if you've pulled them down locally and then need to push them back to your service). If you've done all of the above, update your question with the Node.js script in question so we can see it.

Answer 2

As Chris pointed out, you are most likely still calling request.execute() from your table scripts. By design, this will explicitly talk to the MSSQL database you configured your application with. You will have to edit your table scripts to not perform "request.execute()" and instead interact with the TableService object.
If you follow the tutorial, and do the following:
1. Import the package.
2. Create the table service object.
3. Create an entity (and modify the variables to store the data you need)
4. Write the entity to your table service.
You should see data being written to table storage rather than SQL database.
Give it a shot and ping back, we'll help you out.