-- 'u','U' -返回全是大写的字符串

-- 'l','L' -返回全是小写的字符串

-- 'a','A' -返回大小写结合的字符串

-- 'x','X' -返回全是大写和数字的字符串

-- 'p','P' -返回键盘上出现字符的随机组合

create table test_table as SELECT rownum as col_1,DBMS_RANDOM.string('~',5) as col_2,DBMS_RANDOM.string('L',5) as col_3,DBMS_RANDOM.string('A',5) as col_4,DBMS_RANDOM.string('U',5) as col_5,DBMS_RANDOM.string('X',5) as col_6,DBMS_RANDOM.string('P',5) as col_7 from (SELECT level,ROWNUM rn FROM DUAL CONNECT BY ROWNUM <= 123456)