Question

用ibatis出现出错误请教com.ibatis.common.jdbc.exception.NestedSQLException:

com.ibatis.common.jdbc.exception.NestedSQLException:
--- The error occurred in com/ibeats/Person.xml.
--- The error occurred while applying a parameter map.
--- Check the person1.getPerson-InlineParameterMap.
--- Check the statement (query failed).
--- Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '??' at line 1
at com.ibatis.sqlmap.engine.mapping.statement.MappedStatement.executeQueryWithCallback(MappedStatement.java:201)
at com.ibatis.sqlmap.engine.mapping.statement.MappedStatement.executeQueryForList(MappedStatement.java:139)
at com.ibatis.sqlmap.engine.impl.SqlMapExecutorDelegate.queryForList(SqlMapExecutorDelegate.java:567)
at com.ibatis.sqlmap.engine.impl.SqlMapExecutorDelegate.queryForList(SqlMapExecutorDelegate.java:541)
at com.ibatis.sqlmap.engine.impl.SqlMapSessionImpl.queryForList(SqlMapSessionImpl.java:118)
at com.ibatis.sqlmap.engine.impl.SqlMapSessionImpl.queryForList(SqlMapSessionImpl.java:122)
at com.ibatis.sqlmap.engine.impl.SqlMapClientImpl.queryForList(SqlMapClientImpl.java:98)
at com.ibeats.PersonDaoImpl.findPersons(PersonDaoImpl.java:43)
at com.ibeats.PersonDaoImpl.main(PersonDaoImpl.java:54)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '??' at line 1
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at com.ibatis.sqlmap.engine.execution.SqlExecutor.executeQuery(SqlExecutor.java:185)
at com.ibatis.sqlmap.engine.mapping.statement.MappedStatement.sqlExecuteQuery(MappedStatement.java:221)
at com.ibatis.sqlmap.engine.mapping.statement.MappedStatement.executeQueryWithCallback(MappedStatement.java:189)
... 8 more
Exception in thread "main" java.lang.NullPointerException
at com.ibeats.PersonDaoImpl.main(PersonDaoImpl.java:54)

Answer 1

你好：

1. 首先，在ibatis的sql语句中尽量不要使用 * ，用多少，取多少，这样既能提升执行速度，也不容易出错。

2. 这句报错明显是SQL语句出错了，暂时怀疑是你的SQL语句后面或者前面有不可见字符造成，可以检查下。

3. 可以善用日志来帮忙打出SQL语句进行DEBUG。

希望帮到你。

Answer 2

ou have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '??' at line 1

你的sql语句写错了，如果自己查不出来哪里错了就把sql那部分前后的代码贴出来

追问

sql语句很简单select * from person查所有数据啊！

select * from person