My pl/sql procedure works; I'm just looking for someone to review it

Question

Hi All,
I wrote the below procedure to be executed via APEX (inside the APEX_PLSQL_JOB.SUBMIT_PROCESS wrapper).
It works fine, but I'm not a programmer per se and am just curious if one of the veterans on this forum could review it
and just tell me if it looks like I followed proper standards/procedures etc. or make any suggestions on how I can be more efficient etc.
The purpose of the procedure is to update Oracle Applications translations tables with language-translated values that we have
accumulated from our global workforce. It's pretty simple - just a big find and replace exercise - replacing english values in the apps
tables with translated values. Oracle's '_TL' tables are designed for this purpose and I'm not updating any primary or foriegn keys.
I don't know the exact update statement or instance at the time of execution and hence the need for dynamic SQL and a DB link.
Again, there are no issues (yet) - everything is working fine, I'm just interested in having someone review it and offer me some feedback.
thanks in advance,
John
create or replace
procedure GSE_UPDATE_TL_TABLES (l_instance IN varchar2, l_app_job IN number)
IS
l_tname  varchar2(30);
l_column_name VARCHAR2(30);
l_col_value VARCHAR2(4000);
l_eng_value VARCHAR2(4000);
l_language VARCHAR2(4);
i number;
l_query VARCHAR2(4000);
l_messages dbms_output.chararr;
l_numlines integer := 1000; -- retrieves max 1000 messages from the buffer
l_rows_updated number := 0;
l_rows_processed number;
CURSOR TABLES_CUR IS
SELECT TABLE_NAME, COLUMN_NAME, COLUMN_VALUE, eng_value, LANGUAGE FROM GSE_LNG_STRINGS WHERE COMPLETION_STATUS = 'Y'; ---This table is our repository of translations
and includes the english value, the translated values, the language code and the table and column names that will be updated.
BEGIN
DBMS_OUTPUT.ENABLE(1000000);
delete from gse_update_tracking;  ---I'm using this table to track real-time progress and to update a progress status bar in APEX.
commit;
open tables_cur;
LOOP
fetch tables_cur into l_tname, l_column_name,l_col_value, l_eng_value, l_language;
EXIT WHEN tables_cur%NOTFOUND;
BEGIN
EXECUTE IMMEDIATE
'Update ' ||l_tname||'@'||l_instance||' set ' ||l_column_name|| ' = q''['||l_col_value||']''  where ' ||l_column_name|| ' = q''['||l_eng_value||']'' and language = '''||l_language||'''';
l_rows_updated := (l_rows_updated + sql%rowcount);
insert into gse_update_tracking (counter) values (1);
commit;
exception
  when dup_val_on_index then
l_query := 'Update ' ||l_tname||'@'||l_instance||' set ' ||l_column_name|| ' = q''['||l_col_value||']''  where ' ||l_column_name|| ' = q''['||l_eng_value||']'' and language = '''||l_language||'''';
DBMS_OUTPUT.PUT_LINE('This query caused DUP_VAL_ON_INDEX exception: '||l_query);
when others then
l_query := 'Update ' ||l_tname||'@'||l_instance||' set ' ||l_column_name|| ' = q''['||l_col_value||']''  where ' ||l_column_name|| ' = q''['||l_eng_value||']'' and language = '''||l_language||'''';
DBMS_OUTPUT.PUT_LINE('This caused an undefined exception: '||l_query);
end;
End Loop;
l_rows_processed := tables_cur%rowcount;
update gse_lng_jobs set rows_processed = l_rows_processed, rows_updated = l_rows_updated where job_id = l_app_job;
close tables_cur;
begin
dbms_output.get_lines(l_messages, l_numlines);
for i in 1..l_messages.count
loop
insert into gse_lng_update_exceptions(id, text, Job) values(i, l_messages(i), l_app_job);
commit;
end loop;
end;
END;

Answer 1

Hoek, davidp 2, Tubby, rp0428 et al.,
I think I'm making progress. I'm researching and trying to incorporate your suggestions.
I worked through the examples of error logging here: http://www.oracle.com/technetwork/issue-archive/2006/06-mar/o26performance-096310.html. I'm not sure if this will work for me though since I'm updating many tables and not just one. So it seems I would need to run this for every table that I'm updating?
BEGIN
        DBMS_ERRLOG.CREATE_ERROR_LOG('[table_name]');
END;
Otherwise, this is the current state of things:
create or replace
procedure gse_lng_test_1 (p_table varchar2, p_column varchar2) *--using proper parameter names prefixed with 'p' to distinguish from local variables*
IS
i number;
l_query VARCHAR2(4000);
l_messages dbms_output.chararr;
l_numlines integer := 1000; -- retrieves max 1000 messages from the buffer
l_rows_updated number := 0;
l_rows_processed number;
BEGIN
DBMS_OUTPUT.ENABLE(1000000);
commit;
l_query := 'Update ' ||p_table||' set ' ||p_column|| ' = :newval where '||p_column|| ' = :engval and language = :lang' ; *--build the string once in a local variable with bind variables. Table names and column names are passed via parameters*
for c2 IN (SELECT TABLE_NAME, COLUMN_NAME, COLUMN_VALUE, eng_value, LANGUAGE FROM GSE_LNG_STRINGS WHERE COMPLETION_STATUS = 'Y' and table_name = p_table and column_name = p_column) *--using implicit cursor instead of explicit cursor*
LOOP
BEGIN
EXECUTE IMMEDIATE l_query USING c2.eng_value, c2.column_value, c2.language; *--execute immediate with bind variables*
exception
  when dup_val_on_index then
  dbms_output.put_line('this query caused a dup_val_on_index: '||SQLERRM||' - '||l_query); *--include SQLERRM in message*
when others then
dbms_output.put_line('this query caused an exception: '||SQLERRM||' - '||l_query); *--include SQLERRM in message*
end;
commit;
end loop;
end;Now that the table names and column names are in parameters, I am calling this from APEX as follows:
Begin
for c1 in (select distinct table_name, column_name from gse_lng_strings)
LOOP
gse_lng_test_1 (p_table=> c1.table_name, p_column=>c1.column_name);
end loop;
end;The one thing I need to do is to get a status of the number of rows processed and updated so I can report back to APEX realtime with a jquery counter plugin that I'm using. That was the reason I was inserting records into a dummy table (gse_update_tracking) before. It worked ok but I realize it was a clumsy approach. I'm not to sure how to accomplish that since I don't think I can access sql%rowcount while the loop is running. Is that correct and if so, are there any other options?
I know I still need to deal with my exception handling and I would like to use the DML error logging if at all possible.
Overall though I feel like it's much cleaner and more manageable. Hopefully it's looking better?
thanks again for the education - I really appreciate it,
John