1. Database Programming
PL SQL

2. Handling Exceptions with PL/SQL
• Exception: is an error that occur at run time (during program execution).
When an exception occurs, the PL/SQL block is terminated.
• An exception can be raised:
– Implicitly by the Oracle server.
– Explicitly by the program.

3. Handling Exceptions with PL/SQL
1. Implicitly by the Oracle server: When an oracle error occurs, an associated exception is raised automatically. The exception being raised is a predefined exception. Ex. when no rows are retrieved from the database in a SELECT statement, then PL/SQL raises the exception NO-DATA-FOUND. 2. Explicitly by the program: Explicitly raise an exception by issuing the RAISE statement within the block. The exception being raised may be either user defined or predefined.

4. Example
BEGIN EXCEPTION WHEN NO_DATA_FOUND THEN DBMS_OUTPUT.PUT_LINE ('A SELECT...INTO did not return any row.'); WHEN TOO_MANY_ROWS THEN DBMS_OUTPUT.PUT_LINE ('A SELECT...INTO return multiple rows.'); WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE ('A SELECT...INTO raise an exception.'); END;

5. Evaluation The user should enter 3 num. not >10 … sort them declare
a number(3);
b number(3);
c number(3);
f number(3);
s number(3);
t number(3);
e exception;
begin
a := :a;
b := :b;
c := :c;
if a>10 then
RAISE e;
END if;
if b>10 then
if c>10 then
if a>b and a>c then
f:=a;
if b>c then
s:=b;
t:=c;
else
s:=c;
t:=b;
end if;
elsif b>a and b>c then
f:=b;
if a>c then
s:=a;
t:= c;
t:=a;
elsif c>a and c>b then
f:=c;
if a>b then
t:= b;
DBMS_OUTPUT.PUT_LINE(f || s || t);
EXCEPTION
When e Then
DBMS_OUTPUT.PUT_LINE('Numbers >10 are not acceptable!');
End;
The user should enter 3 num. not >10 … sort them

6. Evaluation
Write pl sql anonyms block which produces the entire Multiplication Table, like: …