Oracle SQL Developer

Utilizing the Main Features of PL/SQLEND;/Example 7–13 shows the use of IF-THEN-ELSEIF-ELSE to determine the salary raisean employee receives based on the hire date of the employee.Example 7–13Using the IF-THEN-ELSEIF StatementDECLAREbonus NUMBER(6,2);emp_id NUMBER(6) := 120;hire_date DATE;BEGINSELECT hire_date INTO hire_date FROM employees WHERE employee_id = 120;IF hire_date > TO_DATE('01-JAN-98') THENbonus := 500;ELSIF hire_date > TO_DATE('01-JAN-96') THENbonus := 1000;ELSEbonus := 1500;END IF;UPDATE employees SET salary = salary + bonus WHERE employee_id = emp_id;END;/7.3.11.2 Conditional Control With the CASE StatementTo choose among several values or courses of action, you can use CASE constructs. TheCASE expression evaluates a condition and returns a value for each case. The casestatement evaluates a condition and performs an action, such as an entire PL/SQLblock, for each case. When possible, rewrite lengthy IF-THEN-ELSIF statements asCASE statements because the CASE statement is more readable and more efficient.Example 7–14 shows a simple CASE statement.Example 7–14Using the CASE-WHEN StatementDECLAREgrade CHAR(1);BEGINgrade := 'B';CASE gradeWHEN 'A' THEN DBMS_OUTPUT.PUT_LINE('Excellent');WHEN 'B' THEN DBMS_OUTPUT.PUT_LINE('Very Good');WHEN 'C' THEN DBMS_OUTPUT.PUT_LINE('Good');WHEN 'D' THEN DBMS_OUTPUT.PUT_LINE('Fair');WHEN 'F' THEN DBMS_OUTPUT.PUT_LINE('Poor');ELSE DBMS_OUTPUT.PUT_LINE('No such grade');END CASE;END;/Example 7–15 determines the salary raise an employee receives based on the currentsalary of the employee and the job Id. This complex example combines the CASEexpression with IF-THEN-ELSE statements.Example 7–15 Using the IF-THEN_ELSE and CASE StatementDECLARE -- declare variablesjobid employees.job_id%TYPE;7-12 SQL Developer Online Help