Creating and Using a SQL Azure Database

Let’s start by creating a SQL Azure database and playing with it a bit. SQL Azure’s signup process and development experience are slightly different from the rest of the Windows Azure storage services.

1. Creating a Database

The first step is to go to http://sql.azure.com and provision an account. Note that this is not the same URL as the one for the rest of the Windows Azure services (which fall under http://windows.azure.com). During the process, you’ll be asked to provide an administrator username and a password to log on to your SQL Azure database instances. After creating an account, you should see something similar to Figure 1.

There are several key elements to note in Figure 1. The DNS name fhdb1swfkd.database.windows.net (easy to pronounce, isn’t it?) is unique to your account. You can think of it as the equivalent of a “server,” and use it where you traditionally use SQL Server’s “server” names—in connection strings, SSMS, and other tools. However, remember that in this case, this DNS entry is just a façade, and in reality your service stems from multiple machines, rather than just one “server.” This façade is required to make the existing tools and frameworks work against the cloud.

Figure 1 also shows a list of databases. By default, you are allocated a master database. This plays a similar role as in the SQL Server world. The next step is to create a database that you can use to create tables and store actual data. To do that, click the Create Database button. This brings up the dialog shown in Figure 2. This sample database is called booktest, but you can obviously call it whatever you want.

You can use this to create a new database and specify the size limit of that database. Currently, SQL Azure supports databases of up to 10 GB in size. Note that the two sizes offered in the drop-down box (1 GB and 10 GB) differ in pricing, so be sure to check the prices for each. The idea here is that, if you have larger data, you shard it by creating multiple databases and spreading the data over them.

Once you’ve created the new database, it should show up as indicated in Figure 3. This screen also shows you the size of all your databases at any given time.

SQLCMD -U [MyUsername]@[MyServername]
-P [MyPassword] -S
[MyServername].database.windows.net -d master
CREATE DATABASE [MyDatabaseName]
GO

2. Adding Firewall Rules

By default, SQL Azure blocks access to your services from any incoming IP address. To change this, you must manually add firewall rules for all the IP addresses from which you plan to access the service.

To look at the current set of firewall rules and to add/modify rules, switch to the Firewall Settings tab, as shown in Figure 4. This lists all the rules you currently have.

One important thing to note here is the checkbox at the top, which asks whether you want to “Allow Microsoft Services access to this server.” This is unchecked by default, which means that any application hosted on Windows Azure cannot talk to your database on SQL Azure. If you plan to host applications on Windows Azure that talk to SQL Azure, you must have this checkbox checked. Don’t worry about your application on Windows Azure being hosted in a different region/data center—SQL Azure does the right networking magic to allow packets through.

Let’s add a firewall rule to allow access from the current machine. Click the Add Rule button to bring up the dialog shown in Figure 5. If you already know the IP address range of the machines from which you will access SQL Azure, you can enter them here.

If you want to allow access from your current machine, use the IP address displayed at the bottom as the range you want to open. This is the external-facing IP address of your current machine, and is typically dynamically assigned by your ISP. Note that, if this IP address changes, you must modify this rule as well. Unfortunately, there’s no good way to know when your ISP will throw you behind a different IP address. You must constantly monitor access to SQL Azure, or use a website such as http://whatismyipaddress.com to figure this out.

At this point, you’re all set. You have a server and a database provisioned. Let’s connect to it!

3. Using SQL Server Management Studio

The primary tool every user of SQL Server uses to connect to and play with a database is SQL Server Management Studio (SSMS). Support for SQL Azure is built into SSMS 2008 R2 (which was available as a CTP as of this writing). Earlier versions will work against SQL Azure, but you must enter queries manually, and most of the GUI integration won’t work.

Open SSMS 2008 R2 to see the dialog shown in Figure 6.

Enter the DNS name from Figure 1. Switch the authentication type to SQL Server Authentication and use the username and password you picked when creating your SQL Azure account.

SSMS will connect to your database and open the Object Explorer, as shown in Figure 7. You can see both the master and the booktest databases you created earlier. If you get a connection error at this stage, check that you’ve set up the right firewall rules in SQL Azure to allow access to your external IP address.

At this point, you can create tables as you normally would. Let’s create a simple table. Execute the code shown in Example 1 using the query editor.

Example 1. Simple table creation

CREATE TABLE Employees(EmpID int primary key, Name varchar(30))
GO

If the query executes successfully, you should see the table displayed in the Object Explorer, as shown in Figure 8.

You can now insert rows into the table and query from it, as shown in Example 2 and Figure 9.

Example 2. Inserting and querying

INSERT INTO Employees (EmpID, Name) VALUES
 (1, 'Michael Scott'),
 (2, 'Jim Halpert'),
 (3, 'Dwight Schrute'),
 (4, 'Pam Halpert'),
 (5, 'Andy Bernard')
GO

SELECT * FROM Employees
GO

This is obviously a trivial example, but it does show that standard SQL concepts and tools work as you would expect with SQL Azure.

4. Using ADO.NET

Coding against SQL Azure is the same as coding against normal SQL Server. The same ODBC/ADO.NET idioms work out of the box. The only difference you should be mindful of here is that SQL Azure doesn’t support switching database contexts. Your sessions must query against objects in the same database for the lifetime of the connection.

Example 3 shows the same listing from Figure 13-9, but querying through ADO.NET using a C# application.

Example 3. Query table using ADO.NET

  var connectionBuilder = new SqlConnectionStringBuilder();
            connectionBuilder.DataSource = "fhdb1swfkd.database.windows.net";
            connectionBuilder.InitialCatalog = "booktest";
            connectionBuilder.Encrypt = true;
            connectionBuilder.UserID = "sriramk";
            connectionBuilder.Password = "<MyPassword>";

            using(var con = new SqlConnection(connectionBuilder.ToString()))
            {
                con.Open();
                using(var command = con.CreateCommand())
                {
                    command.CommandText = "SELECT * FROM Employees";
                    using (var reader = command.ExecuteReader())
                    {
                        while (reader.Read())
                        {
                            Console.WriteLine("EmpID: {0}, Name:{1}",
                                                reader["EmpID"].ToString(),
                                                reader["Name"].ToString());

                        }
                    }
                }

            }