checking that the string does not contain any special character

checking that the string does not contain any special character other then '_':

SELECT NVL(LENGTH(LTRIM(RTRIM(TRANSLATE('RAGHA **NDRA','ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890_',' ')))), 0)
FROM DUAL;

other way:

op_type1 := replace(:blk_cgtm_op_type.op_type,' ','*');

FOR i IN 1 .. length(op_type1)
LOOP
op_char := ASCII(SUBSTR(op_type1,i,1));


IF OP_CHAR not BETWEEN 48 AND 57
and OP_CHAR not BETWEEN 65 AND 90
and OP_CHAR not BETWEEN 97 AND 122
then
l_found := 1;
end if;
END LOOP;

IF L_FOUND = 1
THEN
alert_return := ovpkcs.fn_dispmsg('CG-MNT18',';', ';');
Raise FORM_TRIGGER_FAILURE;

end if;
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