Oracle SQL Developer

Utilizing the Main Features of PL/SQLNULL; -- NULL statement does nothing, allows this block to executed and testedEND;/7.3.8 Assigning Values to a Variable With SELECT INTOAnother way to assign values to a variable is by selecting (or fetching) database valuesinto it. In Example 7–8, 10% of an employee's salary is selected into the bonusvariable. Now you can use the bonus variable in another computation or insert itsvalue into a database table.In the example, DBMS_OUTPUT.PUT_LINE is used to display output from the PL/SQLprogram. For more information, see "Inputting and Outputting Data with PL/SQL" onpage 7-9.Example 7–8Assigning Values to Variables by SELECTing INTODECLARE -- declare and assign valuesbonus NUMBER(8,2);emp_id NUMBER(6) := 100; -- declare variable and assign a test valueBEGIN-- retreive a value from the employees table and assign to the bonus variableSELECT salary * 0.10 INTO bonus FROM employeesWHERE employee_id = emp_id;DBMS_OUTPUT.PUT_LINE ( 'Employee: ' || TO_CHAR(emp_id)|| ' Bonus: ' || TO_CHAR(bonus) ); -- display dataEND;/7.3.9 Inputting and Outputting Data with PL/SQLMost PL/SQL input and output is through SQL statements, to store data in databasetables or query those tables. All other PL/SQL I/O is done through APIs that interactwith other programs. For example, the DBMS_OUTPUT package has procedures such asPUT_LINE. To see the result outside of PL/SQL requires another program, such asSQL*Plus, to read and display the data passed to DBMS_OUTPUT. SQL*Plus does notdisplay DBMS_OUTPUT data unless you first issue the SQL*Plus command SETSERVEROUTPUT ON. For information on SQL*Plus SET command, see SQL*Plus SETCommands .Example 7–9 show the use of DBMS_OUTPUT.PUTLINE. Note the use of SETSERVEROUTPUT ON to enable output.Example 7–9Using DBMS_OUTPUT to Display Output-- enable SERVEROUTPUT in SQL*Plus to display with DBMS_OUTPUT.PUT_LINE-- this enables SERVEROUTPUT for this SQL*Plus session onlySET SERVEROUTPUT ONDECLAREanswer VARCHAR2(20); -- declare a variableBEGIN-- assign a value to a variableanswer := 'Maybe';-- use PUT_LINE to display data from the PL/SQL blockDBMS_OUTPUT.PUT_LINE( 'The answer is: ' || answer );END;/PL/SQL: Usage Information 7-9