add helloworld examples for LTS-9 and LTS-8.

helloworld-8.md

@@ -0,0 +1,24 @@
+### Composing relations (for LTS-8)
+
+Copy the following to "helloworld.hs" for LTS-8:
+
+{% highlight haskell %}
+import Database.Relational.Query
+import Data.Int (Int32)
+
+hello :: Relation () (Int32, String)
+hello = relation $ return (value 0 >< value "Hello")
+
+world :: Relation () (Int32, String)
+world = relation $ return (value 0 >< value "World!")
+
+helloWorld :: Relation () ((Int32, String), String)
+helloWorld = relation $ do
+    h <- query hello
+    w <- query world
+    on $ h ! fst' .=. w ! fst'
+    return $ (,) |$| ((,) |$| h ! fst' |*| h ! snd') |*| w ! snd'
+
+main :: IO ()
+main = putStrLn $ show helloWorld ++ ";"
+{% endhighlight %}

helloworld-9.md

@@ -0,0 +1,24 @@
+### Composing relations (for LTS-9)
+
+Copy the following to "helloworld.hs" for LTS-9:
+
+{% highlight haskell %}
+import Database.Relational.Query
+import Data.Int (Int32)
+
+hello :: Relation () (Int32, String)
+hello = relation $ return (value 0 >< value "Hello")
+
+world :: Relation () (Int32, String)
+world = relation $ return (value 0 >< value "World!")
+
+helloWorld :: Relation () (Int32, String, String)
+helloWorld = relation $ do
+    h <- query hello
+    w <- query world
+    on $ h ! fst' .=. w ! fst'
+    return $ (,,) |$| h ! fst' |*| h ! snd' |*| w ! snd'
+
+main :: IO ()
+main = putStrLn $ show helloWorld ++ ";"
+{% endhighlight %}

quickstart.md

@@ -109,6 +109,10 @@ main :: IO ()
 main = putStrLn $ show helloWorld ++ ";"
 {% endhighlight %}
 
+(You may use older LTS. Please check
+ [LTS-9 - helloworld.hs](helloworld-9.html) or
+ [LTS-8 - helloworld.hs](helloworld-8.html).)
+
 This code defines queries called `hello` and `world`. And `helloworld` composes them by joining them on the first element of the tuples.
 
 This code generates the following SQL statement: