I was wondering the same thing (but with JPA of course). I tried and was getting a message that the members were out of sync.
@ManyToOne(fetch=FetchType.LAZY) @JoinColumn(name="userid", referencedColumnName="id") private User user; and @Column(name="userid") private String userId; How would I go about keeping them in sync? Especially, when someone calls setUser(user) with a new instance that might not have an id. Is there a way in OpenJPA to say that the userId column is only for read-only and not persist operations? Thanks. -Elias Patrick Linskey wrote: > Hi, > > This forum is for the OpenJPA product, so we don't have much > experience with Toplink. > > However, from an OpenJPA standpoint, you can map the same column to > multiple fields without a problem, as long as you don't attempt to set > the fields to different values during the same transaction. > > -Patrick > > On 7/26/07, saravanan_tvm <[EMAIL PROTECTED]> wrote: >> Hi, >> I am using toplink from oracle to support JPA. >> I have the following requirement... >> i have to map same column for multiple properties using @joincolumn >> annotation.. eg its something like this >> >> @joincolumn(name="PARENT_RECORD_ID") >> private Drug drug >> >> @joincolumn(name="PARENT_RECORD_ID") >> private Reaction reaction >> >> PARENT_RECORD_ID is nothing but primary key of parent table. >> but while accessing the application i am getting the following exception.... >> >> MULTIPLE_WRITE_MAPPINGS_FOR_FIELD >> >> Cause: Multiple writable mappings for the field fieldName are defined in the >> descriptor. Exactly one must be defined as writable; the others must be >> specified as read-only. When multiple write mappings are defined for the >> field, TopLink is unable to choose the appropriate mapping for writing the >> value of the field in the database row. Therefore, the exception is raised >> during the validation process of descriptors. >> >> Action: Make one of those mappings read-only >> >> But i cannot make read only, if i make read only then while inserting new >> records it will be problem >> >> please can anyone provide the solution for this... >> Regards, >> Saravanan. >> >> -- >> View this message in context: >> http://www.nabble.com/How-to-map-multiple-properties-to-same-column-as-writable-in-jpa-tf4155235.html#a11822480 >> Sent from the OpenJPA Developers mailing list archive at Nabble.com. >> >> > >
