JPA 函数怎么混合用啊???

HallenYunYun 2008-10-07 04:30:46

就是从数据库中表User某个字段empId,它是由aaa00000类型组成,前三位是不固定的,后五为是按升序累加(不足五位前补0)
现在我要取出后5位最大的一条数据
我用SQL语句:select max(substring(empId,4,5)) from User;这是没有问题的
可是我把它转成含JPA的函数:SELECT MAX(SUBSTRING(e.empId,4,5)) FROM User e 这时会报一个异常:
<openjpa-1.2.0-r422266:683325 nonfatal user error> org.apache.openjpa.persistence.ArgumentException: Encountered ": SUBSTRING" at character 12, but expected: ["(", "+", "-", ":", "?", "ABS", "AVG", "COUNT", "DISTINCT", "LENGTH", "LOCATE", "MAX", "MIN", "MOD", "SELECT", "SIZE", "SQRT", "SUM", <DECIMAL_LITERAL>, <IDENTIFIER>, <INTEGER_LITERAL>].

如果把两个函数分开运行的话,又达不到结果,不分开的话,又报异常...5555555....请高手多多指教...

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