2007/2/19, Jeff Butler <jeffgbutler@gmail.com>:

That's a good solution - then you could deal with object identity yourself.

Jeff Butler

On 2/19/07, Larry Meadors <lmeadors@apache.org > wrote:
..or you could use a rowhandler.

Larry

On 2/19/07, Jeff Butler <jeffgbutler@gmail.com > wrote:

iBATIS groupBy support does not support two independant lists. This would be a very difficult problem to solve and would require us to deal with object identity - which we don't deal with now.

So with groupBy, you can have one and only one list that is automatically populated. Other lists will need to be populated with a nested select.

Jeff Butler

On 2/19/07, Tim.Hammar@mcnichols.com < Tim.Hammar@mcnichols.com > wrote:

Greetings Claudio,

We too have this problem with the latest two releases. If you use version 2.1.7.597 you should have no problems - hopefully you have not implemented any new features like we had (and had to scramble to undo). Versions 2.2 and 2.3 will not handle what you are trying to do. I have been so swamped that I have been unable to generate a test case and submit a bug report. Maybe your example will suffice.

Regards,
Tim Hammar

"Claudio Iacovozzi" <claudio.iacovozzi@googlemail.com >
02/19/2007 06:51 AM

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Subject
Problem with several one to many relationships in breadth

We have a problem filling objects with several '1 to many relationships' in breadth from one single SQL statement. On page 40 of the iBatis Data Mapper Developer Guide the 'groupBy' construct is described as follows: "Using this approach, you can solve any N+1 problem of any depth or breadth." This just seems to work for any depth but NOT for any *breadth*. Example: An insurance agent contains a list of customers as well as a list of insured events. <resultMap class="agent" id="agent" groupBy="id" > <result property="id" column="agentId" /> <result property="firstName" column="agent_firstname" /> <result property="lastName" column="agent_lastname" /> <result property="events" resultMap="event" /> <result property="customers" resultMap="customer" /> </resultMap> <resultMap class="event" id="event" groupBy="id" > <result property="id" column="eventId" /> <result property="title" column="title" /> </resultMap> <resultMap class="customer" id="customer" groupBy="id" > <result property="id" column="customerId" /> <result property="firstName" column="customer_firstname" /> <result property="lastName" column="customer_lastname" /> <result property="street" column="street" /> <result property="city" column="city" /> </resultMap> - The used SQL statement: <select id="getAgent" resultMap="agent" parameterClass="int"> SELECT a.agentId, a.FirstName as agent_firstname, a.LastName as agent_lastname, b.eventId, b.title, c.customerId, c.FirstName as customer_firstname, c.LastName as customer_lastname, c.street, c.city FROM insurance_agent a, agenteventlink ab, insured_event b, customer c WHERE a.agentId = ab.agentId AND ab.eventId = b.eventId AND b.customerId = c.customerId AND a.agentId = #id# ORDER BY a.agentId, c.customerId </select> - The returned result set: agentId,agent_firstname,agent_lastname,eventId,title,customerId,customer_firstname,customer_lastname {1,Agent1,Smith,1,housebreaking,1,Customer1,Johnson} {1,Agent1,Smith,4,theft,1,Customer1,Johnson} {1,Agent1,Smith,2,damage,3,Customer2,Miller} What we would like to achieve is getting a bean of type Agent, which contains two lists of all its customers and all its associated insured events: Agent1 --> List<Customer> {1:Customer1, 3:Customer2} --> List<Event> {1:housebreaking, 2:damage, 4:theft} But iBatis creates a bean like this: Agent1 --> List<Customer> {1: Customer1, 1:Customer1, 3: Customer2} --> List<Event> {1:housebreaking, 2:damage, 4:theft} We want to avoid several SQL statements to get the necessary data (one to get all events, and one to get all customers). Any solution ?