Tabular Forms

Question

Hi,
I am trying, unsuccessfully, to create a multirecord form
against a table called passengers. The reason is probably because the table is empty. Thats why I need a form to enter data !.
Perhaps my approach is wrong, so lets run by the requirements.
I would like to do the following, step by step,
On Page 2 enter a number in a text field then navigate to Page 3 when pressing a "continue" button.
Om Page 3 I automatically generate an X row form with the following text fields (X depends on the value i entered in the text field on Page 2):
name, address, tel, fax etc.....
On pressing a submit button I want to insert these values into a table called passengers, which is initially empty.
If I just create a tabular form on the passengers table I do get any fields, since the table is empty.
Any suggestions how to do this ?
Any suggestions or help appreciated.
best regards,
Mark Battersby
email: [email protected]
BTW: if the table name is like X_Y then the wizard doesn't work. Changing the name to X or Y or XY works fine.

Answer 1

Warning! This is not an HTML DB 101 answer. This is a complex technique to achieve the desired objective.
OK, lets start simple and build on this one. I'm going make use of the all_objects view to get blank rows in my query. Notice I always short-circuit the query with "and rownum < x". all_objects has 20k+ rows and you don't want that many blanks or the performance hit it will incur.
You can try these in SQL Workshop in the SQL command processor. First, lets write the query to for a tabular form on the EMP table:
select htmldb_item.text(1,ename) ||htmldb_item.hidden(2,empno) ename
  from empNotice I concatenated the empno to the same column. If you make it a separate column, the reporting engine will have create a column for your hidden item and this is not a desireable appearence.
Next, lets try a query that matches the previous one, but gives us 10 blank rows:
select ename from(
    select htmldb_item.text(1,null) ||htmldb_item.hidden(2,0) ename
      from all_objects
     where rownum < 11)The next step is to union the two together (union all so we get all of are blank rows and not just one). I am also going to add a column I will alias to OB. This will be my first order by column. I'll set the rows from emp to have an ob of 1 and the blanks to have an ob of 2, that way I can order by ob and the rows with value will always come first. I will then write an inline view around both queries so I can order by the results, yet not display the ob column:
select ename from (
    select htmldb_item.text(1,ename) ||htmldb_item.hidden(2,empno) ename,1 ob
      from emp
     union all
    select ename,ob from(
        select htmldb_item.text(1,null) ||htmldb_item.hidden(2,0) ename,2 ob
          from all_objects
         where rownum < 30))
where rownum < 21 -- you can replace this 21 with :ITEM_NAME to make it dynamic
order by ob,enameI would set the first "where rownum < 30" to a number that is one greater than the maximum rows you ever want to return. The second rownum predicate (where rownum < 21) is for the whole query and is a good candidate for an HTML DB item. This way you can change the max rows on the fly.
To process this, you will need to write a custom process like:
for i in 1..htmldb_application.g_f01.count loop
    if htmldb_application.g_f02(i) = 0 then --inserting
        insert into emp(ename) values (htmldb_application.g_f01(i));
    else --updating
        update emp set ename = htmldb_application.g_f01(i) where empno = htmldb_application.g_f02(i);
    end if;
end loop;Want to really get fancy and only update the values that have changed?
Query:
select ename from (
    -- notice the addition of item 3 which is an md5 checksum of the columns as they exist in the table
    select htmldb_item.text(1,ename) ||htmldb_item.hidden(2,empno)||htmldb_item.md5_hidden(3,ename,empno) ename,1 ob
      from emp
     union all
    select ename,ob from(
          select htmldb_item.text(1,null) ||htmldb_item.hidden(2,0)||htmldb_item.md5_hidden(3,null,null) ename,2 ob
            from all_objects
           where rownum < 30))
where rownum < 21 -- you can replace this 21 with :ITEM_NAME to make it dynamic
order by ob,enameProcess:
declare
     l_md5 varchar2(32767);
begin
    for i in 1..htmldb_application.g_f01.count loop
        if htmldb_application.g_f02(i) = 0 then --inserting
            insert into emp(ename) values (htmldb_application.g_f01(i));
        else --updating
            -- generate another md5 checksum of the columns from the page
            l_md5 := htmldb_item.md5_checksum(htmldb_application.g_f01(i),htmldb_application.g_f02(i));
             -- if they are equal, no update on the page was made.
            if l_md5 != htmldb_application.g_f01(3) then -- value has changed, so update
                update emp set ename = htmldb_application.g_f01(i) where empno = htmldb_application.g_f02(i);
            end if;
        end if;
    end loop;
end;Hope this answers your question,
Tyler