Help with uploading an excel file to a table using an application

Question

Hello,
Can anyone please help me out with this issue. I have apex application where in the end users upload an excel file to a table. For this I have followed the solution provided in this link
http://avdeo.com/2008/05/21/uploading-excel-sheet-using-oracle-application-express-apex/
Using the above solution, I was able to upload the excel data to a table "sample_tbl1" successfully with fields Id,acct_no,owner_name,process_dt. But the thing is I want accomdate a particular condition while uploading the file data, to check see if the acct_no already exists in another table say "sample_tbl2" or not. If acct_nos already exists in sample_tbl2 then give out an error displaying the list of account numbers that already exists in the database. Below is the code which I am using to upload file data to a table.
DECLARE
v_blob_data       BLOB; 
v_blob_len        NUMBER; 
v_position        NUMBER; 
v_raw_chunk       RAW(10000); 
v_char            CHAR(1); 
c_chunk_len       number       := 1; 
v_line            VARCHAR2 (32767)        := NULL; 
v_data_array      wwv_flow_global.vc_arr2; 
v_rows            number; 
v_sr_no           number         := 1; 
l_cnt             BINARY_INTEGER := 0;
l_stepid          NUMBER := 10;
BEGIN
--Read data from wwv_flow_files</span> 
select blob_content into v_blob_data 
from wwv_flow_files 
where last_updated = (select max(last_updated) from wwv_flow_files where UPDATED_BY = :APP_USER) 
and id = (select max(id) from wwv_flow_files where updated_by = :APP_USER); 
v_blob_len := dbms_lob.getlength(v_blob_data); 
v_position := 1; 
/* Evaluate and skip first line of data
WHILE (v_position <= v_blob_len ) LOOP
v_raw_chunk := dbms_lob.substr(v_blob_data,c_chunk_len,v_position);
v_char :=  chr(hex_to_decimal(rawtohex(v_raw_chunk)));
v_line := v_line || v_char;
v_position := v_position + c_chunk_len;
-- When a whole line is retrieved
IF v_char = CHR(10) THEN
-- Clear out 
v_line := NULL;
EXIT;
END IF;
END LOOP;
-- Read and convert binary to char</span> 
WHILE ( v_position <= v_blob_len ) LOOP 
v_raw_chunk := dbms_lob.substr(v_blob_data,c_chunk_len,v_position); 
v_char :=  chr(hex_to_decimal(rawtohex(v_raw_chunk))); 
v_line := v_line || v_char; 
v_position := v_position + c_chunk_len; 
-- When a whole line is retrieved </span> 
IF v_char = CHR(10) THEN
-- Convert comma to : to use wwv_flow_utilities </span> 
v_line := REPLACE (v_line, ',', ':'); 
-- Convert each column separated by : into array of data </span> 
v_data_array := wwv_flow_utilities.string_to_table (v_line); 
-- Insert data into target table
EXECUTE IMMEDIATE 'insert into sample_tbl1(ID,ACCT_NO,OWNER_NAME,PROCESS_DT) 
values (:1,:2,:3,:4)'
USING 
v_sr_no, 
v_data_array(1), 
v_data_array(2),
to_date(v_data_array(3),'MM/DD/YYYY');
-- Clear out 
v_line := NULL; 
v_sr_no := v_sr_no + 1; 
l_cnt := l_cnt + SQL%ROWCOUNT;
END IF; 
END LOOP;
delete from wwv_flow_files
where last_updated = (select max(last_updated) from wwv_flow_files where UPDATED_BY = :APP_USER)
and id = (select max(id) from wwv_flow_files where updated_by = :APP_USER);
l_stepid  := 20;
IF l_cnt = 0 THEN
apex_application.g_print_success_message := apex_application.g_print_success_message || '<p><span style="font-size:14;font-weight:bold">Please select a file to upload.</span></p>' ;
ELSE
apex_application.g_print_success_message := apex_application.g_print_success_message || '<p><span style="font-size:14;font-weight:bold;color:green">File uploaded and processed ' || l_cnt || ' record(s) successfully.</span></p>';
END IF;
l_stepid  := 30;
EXCEPTION WHEN OTHERS THEN
ROLLBACK;
apex_application.g_print_success_message := apex_application.g_print_success_message || '<p><span style="font-size:14;font-weight:bold;color:red">Failed to upload the file. '||REGEXP_REPLACE(SQLERRM,'[('')(<)(>)(,)(;)(:)(")('')]{1,}', '') ||'</span></p>';
END;
{code}
Can anyone please help me, how do i accomdate the condition within my existing code.
thanks,
Orton                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   

Answer 1

Orton,
From your code it appears that the account No comes in the second column of the file = > v_data_array(1)
So You can put a conditional block around the execute immediate code that inserts the records
For instance
  SELECT count(1) INTO ln_account_no_exists from <"sample_tbl2> where account_no = v_data_array(1);
  IF (  ln_account_no_exists > 0 ) THEN
     --Account No: already exists
    <Do what you want to do here >
  ELSE
    EXECUTE IMMEDIATE ...
  END IF:
{code}
Inorder to handle the account no records which exists you can
  <li>Raise an exception
  <li> Write record to table or insert into collection and then use a report region in the page based on this table/collection to show error records
  <li> Append errored account No:s to the Success Message Variable programmatically(this variable is used by PLSQL process success/error message )
   {code}
    IF ( record exists)
      apex_application.g_print_success_message := apex_application.g_print_success_message||','|| v_data_array(1) ; -- Comma separated list of errored account no:s
    ELSE ...
   {code}
Hope it helps