Support Postgres backend in SQLFiddle dropdown.

Author: rspeele

demos/SQLFiddle/SQLFiddle.Website/Views/Home/Index.cshtml

@@ -5,9 +5,10 @@
         <select id="backend">
             <option value="SQLiteFiddle" selected>SQLite</option>
             <option value="TSQLFiddle">T-SQL</option>
+            <option value="PostgresFiddle">Postgres</option>
         </select>
         <span style="float: right">
-            <a href="#A1272D216C3DD2987FE37389215CF7F3113BECB8" style="margin-right: 50px">(example)</a>
+            <a href="#52632EC5A298CFFFD652D53C03DD1318A9DACA3C" style="margin-right: 50px">(example)</a>
             SQL typechecking and translation
             <a href="https://github.com/rspeele/Rezoom.SQL">powered by RZSQL</a>.
             Web interface built with the

demos/SQLFiddle/SQLFiddle/Domain.fs

@@ -7,11 +7,13 @@ let saveFiddle fiddleData = Persistence.saveFiddle fiddleData
 
 let private sqliteBackend = SQLite.SQLiteBackend() :> IBackend
 let private tsqlBackend = TSQL.TSQLBackend() :> IBackend
+let private postgresBackend = Postgres.PostgresBackend() :> IBackend
 
 let private backendOf fiddleBackend =
     match fiddleBackend with
     | SQLiteFiddle -> sqliteBackend
     | TSQLFiddle -> tsqlBackend
+    | PostgresFiddle -> postgresBackend
 
 let private errorFrom ty (exn : SQLCompilerException) =
     let src, reason, message =

demos/SQLFiddle/SQLFiddle/Model.fs

@@ -7,14 +7,17 @@ type FiddleModel = SQLModel<".">
 type FiddleBackend =
     | SQLiteFiddle
     | TSQLFiddle
+    | PostgresFiddle
     override this.ToString() =
         match this with
         | SQLiteFiddle -> "sqlite"
         | TSQLFiddle -> "tsql"
+        | PostgresFiddle -> "postgres"
     static member Parse(str : string) =
         match str with
         | "sqlite" -> Some SQLiteFiddle
         | "tsql" -> Some TSQLFiddle
+        | "postgres" -> Some PostgresFiddle
         | _ -> None
 
 type FiddleId =