1.測試環(huán)境: a: os: microsoft windows xp [版本 5.1.2600] db: oracle9i enterprise edition release 9.2.0.1.0 - production b: os:sunos 5.9 [ solaris 9] db:oracle10g enterprise edition release 10.1.0.3 - production
a.char默認(rèn)長度是1, varchar2必須指出長度 sql> create table test (x char,y varchar2(10)) tablespace users; 表被創(chuàng)建 sql> desc test; name type nullable default comments ---- ------------ -------- ------- -------- x char(1) y y varchar2(10) y
b. 尾部空格比較,對于char類型,’a’=’a ‘,對于varchar2類型，’b’<’b ‘
sql> alter table test modify ( x char(10)); 表被改變 sql> insert into test values('a ','b '); 1 行 已插入 sql> select * from test where x='a '; x y ---------- ---------- a b sql> select * from test where y='b '; x y ---------- ---------- sql> select * from test where y>'b';
