[Feedbac from Mike
John Goerzen <jgoerzen@complete.org>**20071204063602] {
hunk ./en/ch21-databases.xml 7
-      Many different applications have the need to store data in databases.
hunk ./en/ch21-databases.xml 56
+      <para>
+        Another database abstraction library for Haskell is HSQL,
+        which shares a similar purpose with HDBC.  There is also a
+        higher-level framework called HaskellDB, which sits atop
+        either HDBC or HSQL, and is designed to help insulate the
+        programmer from the details of working with SQL.  However, it
+        does not have as broad appeal because its design limits it to
+        certain -- albeit quite common -- database access patterns.
+      </para>
+
hunk ./en/ch21-databases.xml 89
+      <para>
+        If you want to use HDBC with other databases, check out the
+        HDBC Known Drivers page at <ulink
+        url="http://software.complete.org/hdbc/wiki/KnownDrivers"/>.
+        There you will find a link to the ODBC binding, which lets you
+        connect to virtually any database on virtually any platform
+        (Windows, POSIX, and others).  You will also find a PostgreSQL
+        binding.  MySQL is supported via the ODBC binding, and
+        specific information for MySQL users can be found in the
+        <ulink
+        url="http://software.complete.org/hdbc-odbc/static/doc/Database-HDBC-ODBC.html">HDBC-ODBC
+        API documentation</ulink>.
+      </para>
hunk ./en/ch21-databases.xml 166
+      <para>
+        Note that a rollback operation only rolls back the changes
+        since the last &commit;, &rollback;, or &withTransaction;.  A
+        database does not maintain an extensive history like a
+        version-control system, and there are not multiple levels of
+        undo in a database.
+      </para>
hunk ./en/ch21-databases.xml 187
+      <para>
+        You will see examples of &commit; later in this chapter, and
+        examples of &withTransaction; in <remark>FIXME: insert ref to
+        ch22</remark>. 
+      </para>
hunk ./en/ch21-databases.xml 486
+          Here's an example of lazy reading:
+        </para>
+        &query.ghci:far;
+        <para>
+          Note that you could have used
+          <literal>fetchAllRowsAL'</literal> here as well.  However,
+          if you had a large data set to read, it would have consumed
+          a lot of memory.  By reading the data lazily, we can print
+          out extremely large result sets.
hunk ./en/ch21-databases.xml 585
-    </sect1>
-
-    <sect1 id="hs.databases.threading">
-      <title>Threading</title>
-      <para>
-        Different database systems have different capabilities
-        regarding multithreading.  The HDBC API spec suggests that, to
-        be safe, you should not try to issue more than one
-        simultaneous query over a single connection.  Though you may
-        use a single connection serially across multiple threads.
-      </para>
hunk ./examples/ch21/query.ghci 36
+
+--# far
+conn <- connectSqlite3 "test1.db"
+stmt <- prepare conn "SELECT * from test where id < 2"
+execute stmt []
+results <- fetchAllRowsAL stmt
+mapM_ print results
+disconnect conn
hunk ./meta/assignments.txt 25
-JG        21. Talking to databases: Data.Typeable
+JG        21. Talking to databases (DONE)
hunk ./meta/assignments.txt 38
-
+JG     APP C. Data.Typeable
}