It was either not specified and/or could not be found for the javaType (java.util.List) : jdbcType

在使用MyBatis-Plus的时候，他会将实体类以及表字段自动关联起来，但是当我们想要指定额外的一对多关系的时候，例如：
订单保存的时候同时需要保存订单详情列表，此时订单与订单详情列表就是 一对多 的关系，因此在定义订单实体类的时候，我们还需要额外的定义一个订单详情列表集合属性，但是此时在保存订单的时候就会报错：

### Error updating database.  Cause: java.lang.IllegalStateException: Type handler was null on parameter mapping for property 'orderDetails'. It was either not specified and/or could not be found for the javaType (java.util.List) : jdbcType (null) combination.
### The error may exist in com/soberw/mall/dao/MallOrderDao.java (best guess)
### The error may involve com.soberw.mall.dao.MallOrderDao.insert
### The error occurred while executing an update
### Cause: java.lang.IllegalStateException: Type handler was null on parameter mapping for property 'orderDetails'. It was either not specified and/or could not be found for the javaType (java.util.List) : jdbcType (null) combination.] with root cause

java.lang.IllegalStateException: Type handler was null on parameter mapping for property 'orderDetails'. It was either not specified and/or could not be found for the javaType (java.util.List) : jdbcType (null) combination.
	at org.apache.ibatis.mapping.ParameterMapping$Builder.validate(ParameterMapping.java:119) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.mapping.ParameterMapping$Builder.build(ParameterMapping.java:104) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.builder.SqlSourceBuilder$ParameterMappingTokenHandler.buildParameterMapping(SqlSourceBuilder.java:143) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.builder.SqlSourceBuilder$ParameterMappingTokenHandler.handleToken(SqlSourceBuilder.java:87) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.parsing.GenericTokenParser.parse(GenericTokenParser.java:77) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.builder.SqlSourceBuilder.parse(SqlSourceBuilder.java:50) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.scripting.xmltags.DynamicSqlSource.getBoundSql(DynamicSqlSource.java:42) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.mapping.MappedStatement.getBoundSql(MappedStatement.java:305) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.executor.statement.BaseStatementHandler.<init>(BaseStatementHandler.java:64) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.executor.statement.PreparedStatementHandler.<init>(PreparedStatementHandler.java:41) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.executor.statement.RoutingStatementHandler.<init>(RoutingStatementHandler.java:46) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.session.Configuration.newStatementHandler(Configuration.java:681) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.executor.SimpleExecutor.doUpdate(SimpleExecutor.java:48) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.executor.BaseExecutor.update(BaseExecutor.java:117) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.executor.CachingExecutor.update(CachingExecutor.java:76) ~[mybatis-3.5.9.jar:3.5.9]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
	at org.apache.ibatis.plugin.Invocation.proceed(Invocation.java:49) ~[mybatis-3.5.9.jar:3.5.9]
	at com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor.intercept(MybatisPlusInterceptor.java:106) ~[mybatis-plus-extension-3.5.1.jar:3.5.1]
	at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:62) ~[mybatis-3.5.9.jar:3.5.9]
	at jdk.proxy2/jdk.proxy2.$Proxy97.update(Unknown Source) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
	at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:64) ~[mybatis-3.5.9.jar:3.5.9]
	at jdk.proxy2/jdk.proxy2.$Proxy97.update(Unknown Source) ~[na:na]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:194) ~[mybatis-3.5.9.jar:3.5.9]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.insert(DefaultSqlSession.java:181) ~[mybatis-3.5.9.jar:3.5.9]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:427) ~[mybatis-spring-2.0.7.jar:2.0.7]
	at jdk.proxy2/jdk.proxy2.$Proxy76.insert(Unknown Source) ~[na:na]
	at org.mybatis.spring.SqlSessionTemplate.insert(SqlSessionTemplate.java:272) ~[mybatis-spring-2.0.7.jar:2.0.7]
	at com.baomidou.mybatisplus.core.override.MybatisMapperMethod.execute(MybatisMapperMethod.java:59) ~[mybatis-plus-core-3.5.1.jar:3.5.1]
	at com.baomidou.mybatisplus.core.override.MybatisMapperProxy$PlainMethodInvoker.invoke(MybatisMapperProxy.java:148) ~[mybatis-plus-core-3.5.1.jar:3.5.1]
	at com.baomidou.mybatisplus.core.override.MybatisMapperProxy.invoke(MybatisMapperProxy.java:89) ~[mybatis-plus-core-3.5.1.jar:3.5.1]
	at jdk.proxy2/jdk.proxy2.$Proxy79.insert(Unknown Source) ~[na:na]
	at com.baomidou.mybatisplus.extension.service.IService.save(IService.java:63) ~[mybatis-plus-extension-3.5.1.jar:3.5.1]
	at com.soberw.mall.service.impl.MallOrderServiceImpl.save(MallOrderServiceImpl.java:91) ~[classes/:na]
	at com.soberw.mall.service.impl.MallOrderServiceImpl.save(MallOrderServiceImpl.java:29) ~[classes/:na]
	at com.soberw.mall.service.impl.MallOrderServiceImpl$$FastClassBySpringCGLIB$$303bc1b3.invoke(<generated>) ~[classes/:na]
	at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) ~[spring-core-5.3.19.jar:5.3.19]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:793) ~[spring-aop-5.3.19.jar:5.3.19]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.3.19.jar:5.3.19]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:763) ~[spring-aop-5.3.19.jar:5.3.19]
	at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:123) ~[spring-tx-5.3.19.jar:5.3.19]
	at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:388) ~[spring-tx-5.3.19.jar:5.3.19]
	at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:119) ~[spring-tx-5.3.19.jar:5.3.19]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.19.jar:5.3.19]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:763) ~[spring-aop-5.3.19.jar:5.3.19]
	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:708) ~[spring-aop-5.3.19.jar:5.3.19]
	at com.soberw.mall.service.impl.MallOrderServiceImpl$$EnhancerBySpringCGLIB$$cb9b51f3.save(<generated>) ~[classes/:na]
	at com.soberw.mall.controller.MallOrderController.insert(MallOrderController.java:82) ~[classes/:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-5.3.19.jar:5.3.19]
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) ~[spring-web-5.3.19.jar:5.3.19]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117) ~[spring-webmvc-5.3.19.jar:5.3.19]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) ~[spring-webmvc-5.3.19.jar:5.3.19]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) ~[spring-webmvc-5.3.19.jar:5.3.19]
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.19.jar:5.3.19]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1067) ~[spring-webmvc-5.3.19.jar:5.3.19]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963) ~[spring-webmvc-5.3.19.jar:5.3.19]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.19.jar:5.3.19]
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) ~[spring-webmvc-5.3.19.jar:5.3.19]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:681) ~[tomcat-embed-core-9.0.62.jar:4.0.FR]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.19.jar:5.3.19]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) ~[tomcat-embed-core-9.0.62.jar:4.0.FR]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.62.jar:9.0.62]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at com.alibaba.druid.support.http.WebStatFilter.doFilter(WebStatFilter.java:124) ~[druid-1.2.9.jar:1.2.9]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.19.jar:5.3.19]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.19.jar:5.3.19]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.19.jar:5.3.19]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.19.jar:5.3.19]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.19.jar:5.3.19]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.19.jar:5.3.19]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:890) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1743) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
	at java.base/java.lang.Thread.run(Thread.java:833) ~[na:na]

根本原因就是：

找不到定义的订单详情列表属性的映射字段
肯定找不到啊，因为我们在数据库中就没有定义订单详情的字段，因此在保存的时候忽略掉这个属性就可以了

实现方式很简单：
==在将要忽略的属性上面添加 @TableField(exist = false)==注解即可：

    //订单详情列表
    @TableField(exist = false)  //标志此属性不是表的字段
    private List<MallOrderDetail> orderDetails;