1. Oracle – PL/SQL
Code for Sample Projects
I. Use of multiple cursors and parameters to create reports.
DECLARE
CURSOR c_region IS SELECT * FROM wf_world_regions WHERE region_name LIKE '%America%' ORDER BY region_name;
CURSOR c_country (p_regionId NUMBER) IS
SELECT * FROM wf_countries WHERE region_id = p_regionId ORDER BY country_name;
CURSOR c_language (p_countryID NUMBER) IS Select l.language_id, language_name, country_id
FROM wf_spoken_languagessl, wf_languages l
WHERE sl.language_id = l.language_id
AND country_id = p_countryID ORDER BY language_name;
BEGIN
FOR v_regionRec IN c_region
LOOP
DBMS_OUTPUT.PUT_LINE(v_regionRec.region_id ||' '|| v_regionRec.region_name);
DBMS_OUTPUT.PUT_LINE('----------');
FOR v_countryRec IN c_country (v_regionRec.region_id)
LOOP
DBMS_OUTPUT.PUT_LINE(v_countryRec.country_name||' '||v_countryRec.area||' '|| v_countryRec.population);
FOR v_languageRec IN c_language (v_countryRec.country_id)
LOOP
DBMS_OUTPUT.PUT_LINE('-----'||v_languageRec.language_name);
END LOOP;
END LOOP;
DBMS_OUTPUT.PUT_LINE(' ');
END LOOP;
END;

2. II. Handling User Defined Exceptions.
DECLARE
v_dept_idexcep_emps.department_id%TYPE;
v_count NUMBER;
BEGIN
v_dept_id := 40;
SELECT COUNT(*) INTO v_count
FROM excep_emps
WHERE department_id = v_dept_id;
IF v_count = 0 THEN
RAISE_APPLICATION_ERROR(-20203,'There are no employees in this department');
END IF;
DBMS_OUTPUT.PUT_LINE('There are ' || v_count || ' employees');
DELETE FROM excep_emps
WHERE department_id = v_dept_id;
IF SQL%ROWCOUNT = 0 THEN
RAISE_APPLICATION_ERROR(-20204, 'No employees were deleted');
END IF;
DBMS_OUTPUT.PUT_LINE(SQL%ROWCOUNT ||
' employees were deleted');
ROLLBACK;
END;

3. III. Creating Functions.

4. IV. Creating Packages with Overloaded Procedures.

5. V. Creating Triggers to maintain data integrity where check constraints would be ineffective.