Answer Posted / hari kanth

ya,we can create trigger on that table
like as follows
CREATE OR REPLACE TRIGGER key_gen
BEFORE INSERT ON <table_name>
FOR EACH ROW
DECLARE
v_num NUMBER(5);
BEGIN
SELECT seq.nextval INTO v_num from dual;
:new.id:=SAM||LPAD(v_num,3,0);
END;

the <table_name> structure like as follows
(id VARCHAR2(20),
name VARCHAR2(15)
)
now you can just add the records like as follows
INSERT INTO <table_name>
(
name
)
VALUES
(
'&Name'
);
then trigger will fires and automatically it will inserts
into that table with out our knowledge.

NOTE:here "seq" is forward sequence.if it start with 1 and
incremented by 1 then the output will be like as follows

select * from <table_name>

id name

SAM001 TV
SAM002 LCD

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