Hi Collin, If you can do it with straight-up JDBC, you can probably do it with iBATIS. I sense you may be looking for some magic in the form of avoiding N+1 selects.
Based on your example, perhaps the following two value objects are called for: UserVO Integer id; String firstName; String lastName; // List of UserPropertyVOs List userProperties; UserPropertyVO Integer id; Integer userId; String propertyName; String propertyValue; If you structure your result set properly and specify some result maps per the examples in the Developers Guide, you can probably get iBATIS to cough up a List of UserVOs that each contain a List of UserPropertyVOs. It would be up to your application to read/eat/loop the data from there. Perhaps there are other strategies as well. Ted On 27/02/07, Collin Peters <[EMAIL PROTECTED]> wrote:
Does iBatis have any kind of built-in support for entity-attribute-value (EAV) style tables? An EAV table (or key-value table) is one where the data is represented in rows instead of in columns. A simple example is here: http://www.devshed.com/c/a/MySQL/Database-Design-Using-KeyValue-Tables/ So for example, if you had a users table such as: USERS ---------- user_id integer, firstname text, lastname text And you needed to represent properties for each users, you could add a few new columns: property1 text, property2 text, etc... But the problem is that you are locked down by the columns. i.e. for each property you add, you need a to add a column to represent that property. EAV would re-structure this by having another table called user_properties which would look like: user_property_id integer, user_id integer, property_name text, property_value text, So you gain flexibility at the cost of complexity. We have a situation like this and I am wondering if iBatis can do some kind of magic to convert the properties automatically. Let me know if you need a more concrete example to understand this. Before I spend the time to do that I will see if anyone has any comments. Regards, Collin Peters
