JDK版本：1.8
框架：SpringBoot 2.x
ORM：JPA
在表的映射实体添加一个属性，而数据表中不必添加该字段。
执行查询数据后，报出如下异常：
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'scheduling0_.res_name' in 'field list' at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) at java.lang.reflect.Constructor.newInstance(Unknown Source) at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) at com.mysql.jdbc.Util.getInstance(Util.java:408) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:944) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3976) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3912) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2530) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2683) at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2486) at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1858) at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1966) at com.alibaba.druid.filter.FilterChainImpl.preparedStatement_executeQuery(FilterChainImpl.java:3188) at com.alibaba.druid.filter.FilterEventAdapter.preparedStatement_executeQuery(FilterEventAdapter.java:465) at com.alibaba.druid.filter.FilterChainImpl.preparedStatement_executeQuery(FilterChainImpl.java:3185) at com.alibaba.druid.wall.WallFilter.preparedStatement_executeQuery(WallFilter.java:640) at com.alibaba.druid.filter.FilterChainImpl.preparedStatement_executeQuery(FilterChainImpl.java:3185) at com.alibaba.druid.filter.FilterEventAdapter.preparedStatement_executeQuery(FilterEventAdapter.java:465) at com.alibaba.druid.filter.FilterChainImpl.preparedStatement_executeQuery(FilterChainImpl.java:3185) at com.alibaba.druid.proxy.jdbc.PreparedStatementProxyImpl.executeQuery(PreparedStatementProxyImpl.java:181) at com.alibaba.druid.pool.DruidPooledPreparedStatement.executeQuery(DruidPooledPreparedStatement.java:228) at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:60) ... 101 more
报出上面的异常，说明即使不加 @Column 注解，JPA也会持久化该字段。
JPA不持久化某字段的解决方案
@Transient 注解表示该属性并非一个到数据库表的字段的映射，ORM框架将忽略该属性。
这样查询，添加等操作就不会报错了。查询时，单独逻辑对此属性进行赋值处理，做扩展就可以了。
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