八月 16, 2018 8:47:40 下午 org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [DispatcherServlet] in context with path [/RPCExamSystem] threw exception [Request processing failed; nested exception is org.hibernate.exception.GenericJDBCException: 無效的列型別: 16] with root cause
java.sql.SQLException: 無效的列型別: 16
	at oracle.jdbc.driver.OracleStatement.getInternalType(OracleStatement.java:3963)
	at oracle.jdbc.driver.OraclePreparedStatement.setNullCritical(OraclePreparedStatement.java:4596)
	at oracle.jdbc.driver.OraclePreparedStatement.setNull(OraclePreparedStatement.java:4578)
	at oracle.jdbc.driver.OraclePreparedStatementWrapper.setNull(OraclePreparedStatementWrapper.java:1285)
	at org.apache.commons.dbcp.DelegatingPreparedStatement.setNull(DelegatingPreparedStatement.java:108)
	at org.apache.commons.dbcp.DelegatingPreparedStatement.setNull(DelegatingPreparedStatement.java:108)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at org.hibernate.engine.jdbc.internal.proxy.AbstractStatementProxyHandler.continueInvocation(AbstractStatementProxyHandler.java:122)
	at org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81)
	at $Proxy47.setNull(Unknown Source)
 

如圖：出現此類錯誤

報java.sql.SQLException: 無效的列型別: 16 的錯誤。

重點在於

at $Proxy47.setNull(Unknown Source)

這個錯誤

表示為資料庫中表的關聯性很強，此表不允許一些欄位為空，

所以檢查插入時的實體是否有不允許為空的，或者嘗試將實體內的所有屬性全部新增，

可將問題解決