Entering query criteria in an item(s)

Question

Hi. In have what I hope is an easy question...
In the same way a user can enter the % character in an item on the canvas to query records where the column is Not Null, can the user enter some special character in the item that will query only records where the value is null?

Answer 1

Hi There:
Try this, it works for me.
Add the block trigger called PRE-QUERY with the following code:
DECLARE
     VV_DEFAULT_WHERE VARCHAR2(500);
BEGIN
     IF :AEMS_PRUEBA.PHONE = '!'
          THEN
          :AEMS_TEST.PHONE := NULL;
          VV_DEFAULT_WHERE := 'AEMS.SEQ IN (SELECT P.SEQ FROM AEMS_TEST P WHERE NVL(P.PHONE, ''!'') = ''!'')';
          SET_BLOCK_PROPERTY('AEMS_TEST', DEFAULT_WHERE, VV_DEFAULT_WHERE);
     END IF;
END;
In the above code, yo can see I am modifuying the defaul_where of the based-table block. The block is called 'AEMS_TEST'.
To do this, I create a local variable called VV_DEFAULT_WHERE. I use an If statement to ask for the special character you want to search for, in my test I ask for the '!'. If the the filed :AEMS_TEST.PHONE = '!' then I do the following:
I nullify the field :AEMS_TEST.PHONE. Then add the where condition the block will use to retrieve the information form the database, as you request retrieving all the records in the table which are equal to null but using a special character instead of living null the field on the block, so I wrote the following code:
VV_DEFAULT_WHERE := 'AEMS.SEQ IN (SELECT P.SEQ FROM AEMS_TEST P WHERE NVL(P.PHONE, ''!'') = ''!'')';
Where AEMS.SEQ is the field on the block [AEMS is the alias of the block]
after that, just need to setup the new where clause of your based-table block with the following code:
SET_BLOCK_PROPERTY('AEMS_TEST', DEFAULT_WHERE, VV_DEFAULT_WHERE);
Then when your user press the F8 to execute the trigger, it will send to the database the following select statement:
SELECT AEMS.NAME,
AEMS.ADRESS,
AEMS.PHONE,
AEMS.LIMIT,
AEMS.SEQ
FROM AEMS_TEST AEMS
WHERE AEMS.SEQ IN (SELECT P.SEQ FROM AEMS_TEST P WHERE NVL(P.PHONE, '!') = '!'
Hope this works for you-
Abdel Miranda
AEMS Global Group
Panama