To-char举例SQL> SELECT last_name, TO_CHAR(start_date, 2 'fmDdspth "of " Month YYYY fmHH:MI:SS AM') HIREDATE 3 FROM s_emp 4 WHERE start_date LIKE '?'; SQL> SELECT 'Order ‘ || TO_CHAR(id) || 2 ' was filled for a total of ‘ || TO_CHAR(total,'fm$9,999') 3 FROM s_ord 4 WHERE ship_date = '21-SEP-92';