update.

quickstart.md

@@ -20,11 +20,61 @@ To install the Haskell "relational-record" library, type as follows:
 
 ### The first relation
 
-test
+Let's defined our first relation. Copy the following to "hello.hs":
+
+```haskell
+import Data.Int (Int32)
+import Database.Record.Instances ()
+import Database.Relational.Query
+
+hello :: Relation () (Int32, String)
+hello = relation $ return (value 0 >< value "Hello")
+
+main :: IO ()
+main = putStrLn $ show hello ++ ";"
+```
+
+'hello' defines the fist relation. This "SELECT"s a constant tuple value (0,"Hello") from the (virtual) empty table. In other words, this relation just returns (0,"Hello").
+
+Let's run this Haskell code to show what kind of SQL statement is generated:
+
+```shell
+% runghc hello.hs
+SELECT ALL 0 AS f0, 'Hello' AS f1;
+```
+
+OK. Next, let's execute this SQL in SQLite3:
+
+```shell
+% runghc hello.hs | sqlite3 dummy.db
+0|Hello
+```
+
+We got "0|Hello"! Note that "dummy.db" is really a dummy file.
 
 ### Composing relations
 
-test
+```haskell
+import Data.Int (Int32)
+import Database.Record.Instances ()
+import Database.Relational.Query
+
+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), (Int32, String))
+helloWorld = relation $ do
+    h <- query hello
+    w <- query world
+    on $ h ! fst' .=. w ! fst'
+    return $ h >< w
+
+main :: IO ()
+main = putStrLn $ show helloWorld ++ ";"
+```