1:n deletion problem

From: Fan, Bill (AP - Australia) ("Fan,)
Date: Tue Jan 14 2003 - 18:27:47 EST

  • Next message: Craig Miskell: "Re: 1:n deletion problem"

    Hi All,

    I'm having problem to use the X.removeFromYArray(y) function to delete the
    1:n relationship records in the database. I'm using tomcat 4.1.17 + Struts
    1.1 + Cayenne-1.0a5-1.

    It is a project issue management system. There are 4 tables in the user
    management section - Project, Users, Role & ProjectUsers. The tables are
    defined as following (in brief):

      ProjectId int PK
      ProjectName varchar(100)

    Users: (oops, can't use User in MSSQL, don't get confused below... )
      UserId int PK
      Login varchar(50)
      Password varchar(20)

      RoleId int PK
      RoleDesc varchar(50)

      ProjectId int FK
      UserId int FK
      RoleId int FK

    ProjectUsers table holds all the information how the user can access the
    system. When I come to the section to edit/modify the user roles, I need to
    delete the records in this table for a user related to a particular project,
    then add the new ones. The logic related to the deletion process is as

            // 1. get the user object
            Users users = getUsers(ctxt, login);

            // 2. get the all related projectuser objects(regardless what
    project for now)
            List projectuserss = user.getProjectusersArray();

            // 3. iterating through the projectusers list and remove them:
            for (int i=0; i<projectuserss.size(); i++)

            // 4. finally, commit the changes

    No matter what I did, just can't see the DELETE statement generated by
    Cayenne from the tomcat running console, and the database records are not
    removed obviously.

    The users object and the related projectuserss list returned by the
    statements can be verified they are all correct. I've tried to set the users
    object consistence state by using
    users.setPersistenceState(PersistenceStte.MODIFIED) right after I get the
    users object, eventhough it is not the case in the
    RemovePaintingFroGalleryAction example.

    On the other hand, the users.addToProjectusersArray(projectusers) function
    is working perfectly (I've added lot of duplicated records ;- )

    What I'm doing wrong here? Can anyone point me to the right direction?

    Thanks for your help!


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