[ http://issues.apache.org/jira/browse/IBATIS-231?page=comments#action_12359924 ]
Sven Boden commented on IBATIS-231: ----------------------------------- I'm pretty sure this is a non-issue... Why would you use "group by" for a guaranteed 1:1 relationship. You can look at the attachment in JIRA-227 to see an example of 1:1 containment relationship without using "group by". The reason for the List in "group by" is that it's not sure your relationship is 1:1. If more than 1 row would satisfy the "group by" for 1 parent object you need a List to store the children. Unless countered this JIRA can be closed as "invalid". Regards, Sven > Grougby for 1:1 relationship > ---------------------------- > > Key: IBATIS-231 > URL: http://issues.apache.org/jira/browse/IBATIS-231 > Project: iBatis for Java > Type: Wish > Components: SQL Maps > Environment: Windows > Reporter: Leo Tu > > I have two classes, one is Parent(master) another is Child(Detail), but they > are 1:1 relationship, > The question is that in child class contains just one parent object, but i > must use List for getter/setter elsewise > has problem, why ? > =================================================== > // parent > public class CustGroup { > ... > } > // child > public class Cust { > ... > private CustGroup custGroup; // 1:1 > ... > public void setCustGroupjava.util.List custGroupList) { ... } // why it > must be List data type ? > public java.util.List getCustGroup() { ... } // why it must be List data > type ? > ... > } > <resultMap id="CustGroup-result" class="CustGroup"> > ... > </resultMap> > <resultMap id="CUST-result" class="Cust"> > ... > <result property="custGroup" resultMap="CUST_GROUP"/> <!-- 1:1 --> > </resultMap> > =================================================== > 1:1, but groupby must use List for getter/setter, > Can't use > public void setCustGroup(CustGroup custGroup) { ... } // I hope can use > this methd > public CustGroup getCustGroup() { ... } // I hope can use this methd > Best Regards, > Leo -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira