1、如果資料庫欄位允許為null空值，但Mybatis配置檔案沒有為該欄位設定預設值時，如果外界傳入的是空值時將會發生如下錯誤：

DEBUG 11-22 12:25:08 ooo Connection Opened  (JakartaCommonsLoggingImpl.java:27)
org.apache.ibatis.exceptions.PersistenceException:
### Error updating database.  Cause: org.apache.ibatis.type.TypeException: Error setting null parameter.  Most JDBC drivers require that the JdbcType must be specified for allnullable parameters. Cause: java.sql.SQLException: 無效的列型別

### The error may involve com.cdsf.messageplus.warehouse.message.dao.MessageDAO.insertMessage-Inline
### The error occurred while setting parameters
### Cause: org.apache.ibatis.type.TypeException: Error setting null parameter.  Most JDBC drivers require that the JdbcType must be specified for all nullable parameters. Cause: java.sql.SQLException: 無效的列型別
 at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:8)
 at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:100)
 at org.apache.ibatis.session.defaults.DefaultSqlSession.insert(DefaultSqlSession.java:87)
 at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:54)
 at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:35)
 at $Proxy1.insertMessage(Unknown Source)
 at com.cdsf.messageplus.warehouse.message.serviceimpl.MessageServiceImpl.insertMessage(MessageServiceImpl.java:65)
 at com.cdsf.messageplus.warehouse.message.action.MessageAction.saveDraft(MessageAction.java:284)
 at com.cdsf.messageplus.warehouse.message.action.MessageAction.add(MessageAction.java:110)
 at com.cdsf.messageplus.warehouse.message.action.TestSaveMsg.main(TestSaveMsg.java:73)
Caused by: org.apache.ibatis.type.TypeException: Error setting null parameter.  Most JDBC drivers require that the JdbcType must be specified for all nullable parameters. Cause: java.sql.SQLException: 無效的列型別
 at org.apache.ibatis.type.BaseTypeHandler.setParameter(BaseTypeHandler.java:17)
 at org.apache.ibatis.executor.parameter.DefaultParameterHandler.setParameters(DefaultParameterHandler.java:73)
 at org.apache.ibatis.executor.statement.PreparedStatementHandler.parameterize(PreparedStatementHandler.java:61)
 at org.apache.ibatis.executor.statement.RoutingStatementHandler.parameterize(RoutingStatementHandler.java:43)
 at org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:56)
 at org.apache.ibatis.executor.SimpleExecutor.doUpdate(SimpleExecutor.java:28)
 at org.apache.ibatis.executor.BaseExecutor.update(BaseExecutor.java:72)
 at org.apache.ibatis.executor.CachingExecutor.update(CachingExecutor.java:43)
 at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:98)
 ... 8 more
Caused by: java.sql.SQLException: 無效的列型別
 at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)
 at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146)
 at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:208)
 at oracle.jdbc.driver.OracleStatement.getInternalType(OracleStatement.java:3433)
 at oracle.jdbc.driver.OraclePreparedStatement.setNullCritical(OraclePreparedStatement.java:4261)
 at oracle.jdbc.driver.OraclePreparedStatement.setNull(OraclePreparedStatement.java:4250)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
 at java.lang.reflect.Method.invoke(Unknown Source)
 at org.logicalcobwebs.proxool.ProxyStatement.invoke(ProxyStatement.java:100)
 at org.logicalcobwebs.proxool.ProxyStatement.intercept(ProxyStatement.java:57)
 at oracle.jdbc.internal.OraclePreparedStatement$$EnhancerByProxool$$11fe31fb.setNull(<generated>)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
 at java.lang.reflect.Method.invoke(Unknown Source)
 at org.apache.ibatis.logging.jdbc.PreparedStatementLogger.invoke(PreparedStatementLogger.java:53)
 at $Proxy2.setNull(Unknown Source)
 at org.apache.ibatis.type.BaseTypeHandler.setParameter(BaseTypeHandler.java:15)
 ... 16 more
DEBUG 11-22 12:25:08 xxx Connection Closed  (JakartaCommonsLoggingImpl.java:27)

2、解決辦法，需要為空值欄位設定預設值如下：

                #{isLss,jdbcType=DECIMAL},
             
                #{isRead,jdbcType=DECIMAL},
             
               #{desc1,jdbcType=VARCHAR},
             
               #{desc2,jdbcType=VARCHAR}