Master Detail Query automatic query ..Urgent help

Question

In my last question, I asked about how to automatically query a form based on table or master detail and gota good answer. What I actually need to do is also query on the detail, for example
select a.user_id, b.week_ending,b.mon_hrs,b.tues_hrs
from emp_profile a, time_reporting_week b
where user_id = portal30.wwctx_api.get_user
and week_ending = '02-JAN-02'
and a.user_id = b.user_id
So I know that I can query on master table which is emp profile, but I also need to query on week ending which is in detail. Do I change the clause in my form pacjage?Or should I change something in Additional Pl/sql ??

Answer 1

There are two ways to achieve this. Both methods have some drawbacks, so please go through them and choose the one that suits you.
Method 1:
=========
This method does not require altering the form package.
Assumptions : The detail table has a column named WEEK_ENDING.
Steps :-
1> Edit the form and select the query button in the left frame of the master section.
2> For the pl/sql button event handler, choose the action as Query and replace the default code with the following :-
declare
l_where varchar2(4000);
l_where_pre varchar2(4000);
l_where_post varchar2(4000);
l_where_pos integer;
l_week_ending varchar2(4000);
l_lang varchar2(4000);
begin
p_session.get_shadow_value(
p_block_name => 'DETAIL_BLOCK',
p_attribute_name => 'A_WEEK_ENDING',
p_index => 1,
p_value => l_week_ending,
p_language => l_lang);
doQuery;
if l_week_ending is not null then
l_where := p_session.get_value_as_varchar2(
p_block_name => 'DEFAULT',
p_attribute_name => '_DETAIL_WHERE_CLAUSE',
p_index => 1
l_where_pos := instr(l_where,' WHERE ');
l_where_pre := substr(l_where,1,l_where_pos+6);
l_where_post := substr(l_where,l_where_pos+7);
l_where_post := 'week_ending = '||l_week_ending||' and '||l_where_post;
l_where := l_where_pre || l_where_post;
p_session.set_value(
p_block_name => 'DEFAULT',
p_attribute_name => '_DETAIL_WHERE_CLAUSE',
p_value => l_where,
p_index => 1);
QueryDetail(
p_mode => 'QUERY' ,
p_session => p_session);
end if;
end;
3> Click on OK to finish editing the form.
4> Run the form - enter query criteria for the master fields and enter the week-ending criterion in the 1st detail
field under Week Ending. Click the Query button.
Advantage:
You will not lose your changes even if you edit the form later on.
Drawback:
In this method, the querying process will be bit slow as we are querying for the detail records twice.
Once through onQuery and the second time after constructing the new where clause with the additional conditon
for the detail rows.
Method 2
========
This method requires altering the form generated package.
Steps :-
1> In the form package, you will find a onQuery procedure. Towards the end of the procedure, you will find a statement like
"_detail_where_cond" := "_detail_where_cond" || ' WHERE ' || ...
2> As the name of the variable suggests, this where condition will be used while querying the detail block. You need to
add a new clause to this for the week_ending column. Prior to that you need to fetch the shadow value for A_WEEK_ENDING.
3> Your altered code should look something like :-
p_session.get_shadow_value(
p_block_name => 'DETAIL_BLOCK',
p_attribute_name => 'A_WEEK_ENDING',
p_index => 1,
p_value => l_week_ending,
p_language => l_lang);
if l_week_ending is not null then
"_detail_where_cond" := "_detail_where_cond" || ' WHERE WEEK_ENDING = ' || l_week_ending || ' AND ' || --existing code
else
--- use the original code here
"_detail_where_cond" := "_detail_where_cond" || ' WHERE ' || ...
end if;
4> Compile the package body and run the form.
Advantage:
In this method we will be querying the detail rows just once. Unlike in method 1.
Disadvantage:
You will lose your alterations once you create a new version of the form by editing it. You need to recompile the package
after re-introducing your changes.