This code summarizes a search engine source code that: 1) Validates search criteria is entered and returns an error if not. 2) Counts the number of matching records to use as a loop limit. 3) Validates results are found and returns an error if not. 4) Loops through the results, selecting the course details into the search datablock one by one. 5) Returns the cursor to the first record after looping through results.

1. Source Code for Search Engine
DECLARE
i NUMBER (1); ‐‐loop counter
ResultCount NUMBER(3); ‐‐loop value
BEGIN
‐‐Validation Trigger, notify user if there is no search criteria entered
IF :KEYWORD.course_search IS NULL THEN
message('You do not insert any search criteria');
RAISE form_trigger_failure;
ELSE null;
END IF;
/* Count the number of records to be shown in the tabular datablock, based on the users' search
criteria
Put the number of records into a variable ‐ Result Count, which is going to use for the loop limit
Use LIKE and wildcards & for searching records
Use LOWER(or UPPER) to turn all the search case insensitive */
SELECT COUNT(COURSE_CODE) INTO ResultCount FROM COURSE WHERE
LOWER(COURSE_CODE) LIKE '%'||LOWER(:KEYWORD.COURSE_SEARCH)||'%'
OR LOWER(COURSE_NAME) LIKE '%'||LOWER(:KEYWORD.COURSE_SEARCH)||'%';
‐‐Validation trigger, notify user if there is no result found
IF ResultCount=0 THEN
message('No courses are found base on your criteria');
RAISE form_trigger_failure;
ELSE null;
END IF;

2. ‐‐Assign the value of i as 1 (notice that we use := for assigning a value, instead of =)
i:=1;
‐‐Move the cursor to COURSE_SEARCH datablock
GO_BLOCK('COURSE_SEARCH');
‐‐Clear the data in the block (i.e., COURSE_SEARCH)
CLEAR_BLOCK(no_validate);
‐‐Put the cursor to the first row of the datablock
First_Record;
‐‐For loop, for i equals 1 to the loop limit
FOR i IN 1..ResultCount
LOOP
/*Select course code, name into the textbox locations
Rownum (with an alias RN) is a system generated "sequence" of records, counts from i=1
to i=loop limit
RN=i means one instance of the records selected */
SELECT COURSE_CODE, COURSE_NAME
INTO :COURSE_SEARCH.COURSE_CODE, :COURSE_SEARCH.COURSE_NAME
FROM (select course_code, course_name, rownum RN from course
WHERE LOWER(COURSE_CODE) LIKE '%'||LOWER(:KEYWORD.COURSE_SEARCH)||'%'
OR LOWER(COURSE_NAME) LIKE '%'||LOWER(:KEYWORD.COURSE_SEARCH)||'%')
WHERE RN=i;
‐‐Put the cursor to the next record
Next_Record;
END LOOP;
‐‐Put the cursor back to the first record
First_Record;
‐‐Put the cursor back to the Search textbox
Go_Block('KEYWORD');
END;