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List:       turbine-torque-dev
Subject:    Using idmethod native with Interbase
From:       Gert Märzendorfer <gert.maerzendorfer () gmx ! net>
Date:       2002-06-25 19:59:47
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I'm  currently  evaluating  Torque  3.0b2  against an existing database running
under InterBase WI-V6.0.1.0 (JDBC driver InterClient 1.60.1). One k.o. criteria
is  the  usage  of  generators  (equivalent to Oracle sequences). Unfortunately
inserting  a  new  record  results in an exception, if selected the "native" id
method:

  org.apache.torque.TorqueException: IdGenerator for table 'TASK' is null
      at org.apache.torque.util.BasePeer.doInsert(Unknown Source)
      at substral.om.BaseTaskPeer.doInsert(BaseTaskPeer.java:192)
      at substral.om.BaseTaskPeer.doInsert(BaseTaskPeer.java:490)
      at substral.om.BaseTask.save(BaseTask.java:841)
      at substral.om.BaseTask.save(BaseTask.java:806)
      at substral.om.BaseTask.save(BaseTask.java:789)
      at TestTorque.Insert.SimpleInsert(Insert.java:26)
      at TestTorque.Insert.main(Insert.java:42)
  SimpleInsert: IdGenerator for table 'TASK' is null

A  look  inside the generated source code shows that DatabaseMap.addIdGenerator
(String   type,   IdGenerator  idGen)  is  called  for  the  above  table  with
type="native" and idGen=null!?

Diving  deeper  into the source of Torque lead me to the following steps, which
will enable Torque using a native idbroker in connection with Interbase:

(1)   Additional   generation   of   setPrimaryKeyMethodInfo()   statement   in
<Table>MapBuilder.java files: tMap.setPrimaryKeyMethodInfo("<Table>");

(2) Modification to DBInterbase.java:
        
      public String getIDMethodType()
      {
        return SEQUENCE;    // replaces return NO_ID_METHOD;
      }
            
      public String getIDMethodSQL(Object obj)
      {
        return "select * from GET_"+ obj +"_ID";
      }
    
(3)  For  each table, which is designed for usage of native id broker, the user
has to create a generator:
        CREATE GENERATOR "<TABLE>_ID_GEN";

(4)  Furthermore  for  each  of  the  above tables a stored procedure has to be
created  by  the user. Called via "select * from get_<table>_id" it will return
the next id for <table>.
        CREATE PROCEDURE "GET_TASK_ID" RETURNS ("AVALUE" INTEGER) AS
        BEGIN
          avalue = GEN_ID(TASK_ID_GEN,1);
          suspend;
        END
        ^                   
        
Precondition:  Table has to contain a primary key composed of one single column
of Interbase type INTEGER.

Will  there  be  a  way  to integrate this improvement into the next release of
Torque? I'm sure Interbase community will be grateful.

Gert


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