How to insert data from APEX form into two tables

Question

Hi,
I'm running APEX 4.1 with Oracle XE 11g, having two tables CERTIFICATES and USER_FILES. Some of the (useless) fields are cut to reduce information:
CREATE TABLE CERTIFICATES
CERT_ID NUMBER NOT NULL ,
CERT_OWNER NUMBER NOT NULL ,
CERT_VENDOR NUMBER NOT NULL ,
CERT_NAME VARCHAR2 (128) ,
CERT_FILE NUMBER NOT NULL ,
) TABLESPACE CP_DATA
LOGGING;
ALTER TABLE CERTIFICATES
ADD CONSTRAINT CERTIFICATES_PK PRIMARY KEY ( CERT_ID ) ;
CREATE TABLE USER_FILES
FILE_ID NUMBER NOT NULL ,
FILENAME VARCHAR2 (128) ,
BLOB_CONTENT BLOB ,
MIMETYPE VARCHAR2 (32) ,
LAST_UPDATE_DATE DATE
) TABLESPACE CP_FILES
LOGGING
LOB ( BLOB_CONTENT ) STORE AS SECUREFILE
TABLESPACE CP_FILES
STORAGE (
PCTINCREASE 0
MINEXTENTS 1
MAXEXTENTS UNLIMITED
FREELISTS 1
BUFFER_POOL DEFAULT
RETENTION
ENABLE STORAGE IN ROW
NOCACHE
ALTER TABLE USER_FILES
ADD CONSTRAINT CERT_FILES_PK PRIMARY KEY ( FILE_ID ) ;
ALTER TABLE CERTIFICATES
ADD CONSTRAINT CERTIFICATES_USER_FILES_FK FOREIGN KEY
CERT_FILE
REFERENCES USER_FILES
FILE_ID
NOT DEFERRABLE
What I'm trying to do is to allow users to fill out all the certificate data and upload a file in an APEX form. Once submitted the file should be uploaded in the USER_FILES table and all the fields along with CERT_ID, which is the foreign key pointing to the file in the USER_FILES table to be populated to the CERTIFICATES table. APEX wizard forms are based on one table and I'm unable to build form on both tables.
That's why I've created a view (V_CERT_FILES) on both tables and using INSTEAD OF trigger to insert/update both tables. I've done this before and updating this kind of views works perfect. Here is where the problem comes, if I'm updating the view all the data is updated correctly, but if I'm inserting into the view all the fields are populated at CERTIFICATES table, but for USER_FILES only the fields FILE_ID and LAST_UPDATE_DATE are populated. The rest three regarding the LOB are missing: BLOB_CONTENT, FILENAME, MIMETYPE. There are no errors when running this from APEX, but If I try to insert into the view from SQLDeveloper, I got this error:
ORA-22816: unsupported feature with RETURNING clause
ORA-06512: at line 1
As far as I know RETURNING clause in not supported in INSTEAD of triggers, although I didn't have any RETURNING clauses in my trigger (body is below).
Now the interesting stuff, after long tracing I found why this is happening:
First, insert is executed and the BLOB along with all its properties are uploaded to wwv_flow_file_objects$.
Then the following insert is executed to populate all the fields except the BLOB and it's properties, rowid is RETURNED, but as we know RETURNING clause is not supported in INSTEAD OF triggers, that's why I got error:
PARSE ERROR #1918608720:len=266 dep=3 uid=48 oct=2 lid=48 tim=1324569863593494 err=22816
INSERT INTO "SVE". "V_CERT_FILES" ( "CERT_ID", "CERT_OWNER", "CERT_VENDOR", "CERT_NAME", "BLOB_CONTENT") VALUES (:B1 ,:B2 ,:B3 ,:B4, ,EMPTY_BLOB()) RETURNING ROWID INTO :O0
CLOSE #1918608720:c=0,e=11,dep=3,type=0,tim=1324569863593909
EXEC #1820672032:c=3000,e=3168,p=0,cr=2,cu=4,mis=0,r=0,dep=2,og=1,plh=0,tim=1324569863593969
ERROR #43:err=22816 tim=1324569863593993
CLOSE #1820672032:c=0,e=43,dep=2,type=1,tim=1324569863594167
Next my trigger gets in action, sequences are generated, CERTIFICATES table is populated and then USER_FILES, but only the FILE_ID and LAST_UPDATE_DATE.
Finally update is fired against my view (V_CERT_FILES), reading data from wwv_flow_files it populates BLOB_CONTENT, MIMETYPE and FILENAME fields at the specific rowid in V_CERT_FILES, the one returned from the insert at the beginning. Last, file is deleted from wwv_flow_files.
I'm using sequences for the primary keys, this is only the body of the INSTEAD OF trigger:
select user_files_seq.nextval into l_file_id from dual;
select certificates_seq.nextval into l_cert_id from dual;
insert into user_files (file_id, filename, blob_content, mimetype, last_update_date) values (l_file_id, :n.filename, :n.blob_content, :n.mimetype, sysdate);
insert into certificates (cert_id, cert_owner, cert_vendor, cert_name, cert_file) values (l_cert_id, :n.cert_owner, :n.cert_vendor, :n.cert_name, l_file_id);
I'm surprised that I wasn't able to find a valuable source of information regarding this problem, only MOS note about running SQLoader against view with CLOB column and INSTEAD OF trigger. The solution would be to ran it against base table, MOS ID 795956.1.
Maybe I'm missing something and that's why I decided to share my problem here. So my question is how do you create this kind of architecture, insert into two tables with a relation between them in APEX ? I read a lot in the Internet, some advices were for creating custom form with APEX API, create a custom ARP, create two ARP or create a PL/SQL procedure for handing the DML?
Thanks in advance.
Regards,
Sve

Answer 1

Thank you however I was wondering if there was an example available which uses EJB and persistence.