如果不允许改DB设计的话，那就用RTRIM来解决吧。例：
DB：
CREATE TABLE TEST
(
TEST_ID VARCHAR2(64) NOT NULL,
TEST_CHAR CHAR(10),
CONSTRAINT TEST_ID PRIMARY KEY (TEST_ID)
);
INSERT INTO TEST VALUES(,);
(
TEST_ID VARCHAR2(64) NOT NULL,
TEST_CHAR CHAR(10),
CONSTRAINT TEST_ID PRIMARY KEY (TEST_ID)
);
INSERT INTO TEST VALUES(,);
测试代码：
Session session = factory.getCurrentSession();
session.beginTransaction();
List list = session.createQuery("FROM Test WHERE RTRIM(TEST_CHAR) = 'a'").list();
session.close();
assertTrue(list.size() > 0);
session.beginTransaction();
List list = session.createQuery("FROM Test WHERE RTRIM(TEST_CHAR) = 'a'").list();
session.close();
assertTrue(list.size() > 0);
输出结果(ORACLE)：
Hibernate:
select
test0_.TEST_ID as TEST1_0_,
test0_.TEST_CHAR as TEST4_0_
from
TEST test0_
where
rtrim(TEST_CHAR)=
14:09:53,171DEBUG StringType:172 - returning as column: TEST1_0_
14:09:53,187DEBUG StringType:172 - returning as column: TEST4_0_
select
test0_.TEST_ID as TEST1_0_,
test0_.TEST_CHAR as TEST4_0_
from
TEST test0_
where
rtrim(TEST_CHAR)=
14:09:53,171DEBUG StringType:172 - returning as column: TEST1_0_
14:09:53,187DEBUG StringType:172 - returning as column: TEST4_0_
而MySQL不会自动补足空格，同样的代码也是可以适用的：
输出结果(MySQL)：
Hibernate:
select
test0_.TEST_ID as TEST1_0_,
test0_.TEST_CHAR as TEST4_0_
from
TEST test0_
where
rtrim(TEST_CHAR)=
14:09:01,828DEBUG StringType:172 - returning as column: TEST1_0_
14:09:01,828DEBUG StringType:172 - returning as column: TEST4_0_
select
test0_.TEST_ID as TEST1_0_,
test0_.TEST_CHAR as TEST4_0_
from
TEST test0_
where
rtrim(TEST_CHAR)=
14:09:01,828DEBUG StringType:172 - returning as column: TEST1_0_
14:09:01,828DEBUG StringType:172 - returning as column: TEST4_0_