Wiring up Application Logic - Oracle Application Express 4 Recipes - page 73

3. You should now see the Create Validation wizard. In the first page of the

wizard, choose the Item Level Validation item (see Figure 3-2).

Figure 3-2. Selecting the type of validation

4. In the next page of the wizard, select the PATIENTDISCHARGE: 1.

P1_PATIENTSOCIALSECURITYNO (Patientsocialsecurityno) item as the item
to be validated.

5. In the next page, choose the PL/SQL validation method, and next the Function

Returning Boolean PL/SQL validation type.

6. Use the default values in the next (Sequence and Name) step. Proceed to the

next (Validation) step and enter the PL/SQL validation code shown in Listing
3-4.

Listing 3-4. PL/SQL Validation Code

DECLARE
CT INTEGER;
BEGIN
SELECT COUNT(*) INTO CT FROM PAYMENTHISTORY WHERE
SOCIALSECURITYNO = :P1_PATIENTSOCIALSECURITYNO;