Oracle SQL Developer

Utilizing the Main Features of PL/SQLExample 7–6 Using LiteralsDECLARE -- declare and assign variablesnumber1 PLS_INTEGER := 32000; -- numeric literalnumber2 NUMBER(8,3);char1 VARCHAR2(1) := 'x'; -- character literalchar2 VARCHAR2(1000);boolean BOOLEAN := TRUE; -- BOOLEAN literaldate1 DATE := '11-AUG-2005'; -- DATE literaltime1 TIMESTAMP;time2 TIMESTAMP WITH TIME ZONE;BEGINnumber2 := 3.125346e3; -- numeric literalnumber2 := -8300.00; -- numeric literalnumber2 := -14; -- numeric literalchar2 := q'!I'm writing an example string.!'; -- string literalchar2 := 'I''m writing an example string.'; -- need two single quotes heretime1 := '11-AUG-2005 11:01:01 PM'; -- TIMESTAMP literaltime2 := '11-AUG-2005 09:26:56.66 PM +02:00';END;/See Also:■■■Oracle Database SQL Reference for information on the syntax forliterals and the date and time types.Oracle Database Application Developer's Guide - Fundamentals forexamples of performing date and time arithmetic.PL/SQL User's Guide and Reference for information on using literalswith PL/SQL.7.3.7 Declaring and Assigning Variables With DEFAULT or NOT NULLYou can use the keyword DEFAULT instead of the assignment operator to initializevariables. Use DEFAULT for variables that have a typical value. Use the assignmentoperator for variables (such as counters and accumulators) that have no typical value.You can also use DEFAULT to initialize subprogram parameters, cursor parameters,and fields in a user-defined record.Besides assigning an initial value, declarations can impose the NOT NULL constraint sothat assigning a NULL raises an error. The NOT NULL constraint must be followed by aninitialization clause.In Example 7–7 the declaration for avg_days_worked_month uses the DEFAULT toassign a value of 21 and the declarations for active_employee and monthly_salary use the NOT NULL constraint.Example 7–7Using DEFAULT and NOT NULLDECLARE -- declare and assign variableslast_nameVARCHAR2(30);first_nameVARCHAR2(25);employee_idNUMBER(6);active_employee BOOLEAN NOT NULL := TRUE; -- value cannot be NULLmonthly_salaryNUMBER(6) NOT NULL := 2000; -- value cannot be NULLnumber_of_days_worked NUMBER(2);pay_per_dayNUMBER(6,2);employee_count NUMBER(6) := 0;avg_days_worked_month NUMBER(2) DEFAULT 21; -- assign a default valueBEGIN7-8 SQL Developer Online Help