The following lines contain the word 'select', 'insert', 'update' or 'delete':
SELECT 'X'
INTO string_buffer
FROM dual
WHERE TO_NUMBER(arg_low_field) <= TO_NUMBER(arg_high_field);
SELECT 'X'
INTO string_buffer
FROM dual
WHERE arg_low_field <= arg_high_field;
SELECT 'X'
INTO string_buffer
FROM dual
WHERE TO_DATE(arg_low_field,'DD-MON-RR' )
<= TO_DATE(arg_high_field, 'DD-MON-RR');