Optional Multi-Value parameter in BIRT - birt

Question

I have a BIRT report that have 4 optional parameters.
startdate; enddate; stringparam and listparam (multi-value parameter).
I followed "bluish" code on this link How do I set a parameter to a list of values in a BIRT report?
and it works if I give either one or all of the value to the parameter. However, when I leave the parameter blank, I got a blank report (which is incorrect result).
This is my query:
select f1,f2,f3,f4
where f1 >= ? -- startdate parameter
or f2 <= ? -- endate paramter
or f4 = ? -- stringparam
and ( f3 in (''/*?listparam*/) )
I did query on my Oracle db to see what parameter is being passed to my query I got 'NULL' as the VALUE_STRING when I leave the parameters values as blank.
Any help is appreciated.

Answer 1

It sounds like you want to occasionally search for records on one to three of the 4 criteria in the parameters.
There are couple ways to do this:
One way is to use like, and set the default parameter value to % which is the wild card. when the parameter runs it returns all values. Be aware this can be problematic if the fields contain null.
or f4 like ?
So you would need to use something similar to below to return null values.
or (f4 is null
or f4 like ?)
I usually prefer to use "All" as my default parameter value, as you can see in the second "and" we look to see if the parameter value is All, if it is all values for PRODUCTTYPEM1.CATEGORY are returned, if it is anything else it looks for the entered valued in the field PRODUCTTYPEM1.CATEGORY.
where PRODUCTTYPEM1.ACTIVE = 't'
and DEVICE2M1.ISTATUS = 'In Use'
and ( 'All' = ?
or PRODUCTTYPEM1.CATEGORY = ?)
For this to work you will need two parameter entries, the first is for All, the second is for any values other then All.
I only have one Category parameter in the report, the second entry looks at the same parameter a second time if the parameter value is not All
The way this works. (expanded explanation by request)
Opening where statement, and simple second criteria for 'In Use'
where PRODUCTTYPEM1.ACTIVE = 't'
and DEVICE2M1.ISTATUS = 'In Use'
The third criteria is two parts set in parenthesis with an OR statement dividing the two parts
and ( 'All' = ?
or PRODUCTTYPEM1.CATEGORY = ?)
If the value of the parameter is All, then the first part of the statement is met, and the query skips everything thing else in the parenthesis. It is like not have the parameter in your SQL query at all.
If the value of the parameter is NOT all, the first part of the statement is not met so the query looks for the parameter value in field PRODUCTTYPEM1.CATEGORY.
Your final query will probably look something like this, though it is problematic in that we have a Default date of 'All', you probably want to use some kind of date for your default value like Jan 1, 1900.
select f1,f2,f3,f4
where f3 in (''/*?listparam*/)
AND ( 'All' = ?
OR f1 >= ?) -- startdate parameter
AND ( 'All' = ?
OR f2 <= ?) -- endate paramter
AND ( 'All' = ?
OR f4 = ?) -- stringparam