According to the comment above, this should become

```erb
// Database connection string (DSN) for read+write operations
// Format (compatible with PEAR MDB2): db_provider://user:password@host/database
// Currently supported db_providers: mysql, pgsql, sqlite, mssql or sqlsrv
// For examples see http://pear.php.net/manual/en/package.database.mdb2.intro-dsn.php
// NOTE: for SQLite use absolute path: 'sqlite:////full/path/to/sqlite.db?mode=0646'
<% if db[:driver] == 'sqlite' -%>
$config['db_dsnw'] = 'sqlite:///<%= db[:database] %>?mode=0646';
<% else -%>
$config['db_dsnw'] = "<%= db[:driver] %>://<%= db[:username] %>:<%= db[:password] %>@<%= db[:host] %>/<%= db[:database] %>";
<% end -%>
```

I.e. use comments from the example config file, and use (adapted) code from the old config file.