PL/SQL structure
Unnamed blocks: unnamed block
Named blocks: procedures, functions, packages, and triggers
Definition section: used to define variables, constants, cursors, triggers, compound data types
Executive part: used to implement the function of the application module, including PL/SQL statements and SQL statements to be executed
Exception handling part: used to handle possible running errors in the execution part
[DECLARE
...-definition section]
BEGIN
..-- the executive part
[EXCEPTION
.-- exception handling part]
END
-
DECLARE
A NUMBER
BEGIN
ARV 1: 2
DBMS_OUTPUT.PUT_LINE ('1 / 2 / 1 / 2 / 2) | | a)
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE ('exception')
END
/
Conditional branching statement:
DECLARE
A1 number: = 100
A2 number: = 200
BEGIN
IF A1 > a2 THEN
DBMS_OUTPUT.PUT_LINE ('A1 is larger than a2')
ELSIF a1=a2 THEN
DBMS_OUTPUT.PUT_LINE ('A1 is equal to a2')
ELSE
DBMS_OUTPUT.PUT_LINE ('A1 is smaller than a2')
ENDIF
END
/
DECLARE
Grade CHAR (1): ='B'
Appraisal VARCHAR2 (20)
BEGIN
Appraisal: =
CASE grade
WHEN'A 'THEN' excellent'
WHEN'B' THEN 'good'
WHEN'C 'THEN'
WHEN'D' THEN 'pass'
WHEN'F'THEN 'failed'
ELSE 'does not have such a rating'
DBMS_OUTPUT.PUT_LINE ('Grade' | | grade | |' is' | | appraisal)
END
/
Loop statement:
DECLARE
Total number: = 0
Salary number: = 1800
BEGIN
LOOP
Total: = total + salary
EXIT WHEN total > 2500
END LOOP
DBMS_OUTPUT.PUT_LINE ('total salary is' | | total)
END
/
DECLARE
Total number: = 0
Salary number: = 1800
BEGIN
WHILE total
