Add method to determine if database exists

+semver:minor

Database.cs

@@ -65,6 +65,22 @@ string[] ParseScript(string script)
 			return goEx.Split(script).Where(c => !goEx.IsMatch(c) && !String.IsNullOrWhiteSpace(c)).ToArray();
 		}
 
+		public bool Exists(string connectionString)
+		{
+			var builder = new SqlConnectionStringBuilder(connectionString);
+
+			string database = builder.InitialCatalog;
+			builder.InitialCatalog = "";
+
+			int count;
+			using (var conn = new SqlConnection(builder.ToString()))
+			{
+				count = conn.Query<int>("select count(*) from sysdatabases where [Name] = @database", new { database }).SingleOrDefault();
+			}
+
+			return count > 0;
+		}
+
 		public void Rebuild(string connectionString)
 		{
 			var builder = new SqlConnectionStringBuilder(connectionString);

README.md

@@ -24,6 +24,16 @@ or
 var db = new Database(typeof(MyType).Assembly, "MyAssembly.Weird.Namespace.Folder1"); //specify what namespace the embedded create & clear sql scripts are in
 ```
 
+### Check if Database Exists
+
+To check if a database exists:
+
+```cs
+bool exists = db.Exists("server=.\\sqlexpress;database=mydb;integrated security=true;");
+```
+
+It will return `true` or `false` depending on if the database in the connection string exists or not.
+
 ### Build a Database
 
 To build a new database using the `create.sql` script: