[Springframework-developer] New JDBC functionality for 1.3

[Thomas R. <tho...@tr...>]

I was talking to Mark last weekend about data access for Spring.NET  
and we discussed the .NET class SqlCommand that provides a nice and  
clean interface to the ADO.NET functionality.  It got me thinking,  
and after adding the support for named parameters, I counted over 75  
different methods for interfacing with the JdbcTemplate - that's a  
lot :)

So, I started looking at providing a SqlCommand interface on top of  
JdbcTemplate to just present the most used features and limit the  
sometimes bewildering number of options for how to pass in the  
parameters etc.  I decided to only support the new named parameter  
support.  The old position based array style is still available from  
the JdbcTemplate directly.  I added a new class  
org.springframework.jdbc.command.SqlCommand to the sandbox.  It's  
simply a number of one-line wrappers on top of the JdbcTemplate.   
Combined with the new named parameter support, it provides a simpler  
interface IMHO.

Here are a few examples:

         SqlCommand listOfBeersCommand = new SqlCommand("select id,  
brand, price from beers", dataSource);
         List beerList = listOfBeersCommand.executeQuery(new  
BeerMapper());

         SqlCommand priceCommand = new SqlCommand("select price from  
beers where brand = :brand", dataSource);
         Map parameters = new HashMap();
         parameters.put("brand", "Heineken");
         Number price = (Number)priceCommand.executeScalar(parameters);

Also, with the new option of passing in a JavaBean as the holder of  
the parameter values (SqlParameterBeanWrapper) it does provide the  
option of using the following code:

         SqlCommand readCommand = new SqlCommand("select id, brand,  
price from beers where id = :id", dataSource);
         SqlCommand saveCommand = new SqlCommand("update beers set  
brand = :brand, price = :price where id = :id", dataSource);

         Map parameters = new HashMap();
         parameters.put("id", new Long(2));
         Beer beer = (Beer)readCommand.executeObject(new BeerMapper 
(), parameters);

         beer.setPrice(new BigDecimal("49.87"));

         SqlNamedParameters updateValues = new SqlParameterBeanWrapper 
(beer);
         int updateCount = saveCommand.executeUpdate(updateValues);

All this is in CVS now (SqlCommand is in the sandbox) and if you have  
any feedback, I'm all ears.

Thomas