数据库中添加了一个字段出现的错误：com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException，解决方案

    今天在做user删除时，在数据库中user表中添加了一个state字段，一开始没有判断非空，如下图所示：

      但是在做数据添加的时候，就是添加不了状态，于是我想把state选上非空，开始直接选中非空是会弹出一个错误框，如下图所示：

   我的解决方案是：先把state这个字段删除，然后再添加state这个字段：

重新添加完state这个字段，数据表的数据如下图所示：

Java中的实体类和接口也都有重新生成（我用的是逆向工程生成），但是运行时出现了如下错误：

Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Column 'state' cannot be null

; SQL []; Column 'state' cannot be null; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Column 'state' cannot be null] with root cause

com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Column 'state' cannot be null

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)

at java.lang.reflect.Constructor.newInstance(Constructor.java:423)

at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)

at com.mysql.jdbc.Util.getInstance(Util.java:387)

at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:932)

at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3878)

at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3814)

at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2478)

at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2625)

at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2551)

at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1861)

at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:1192)

at com.alibaba.druid.pool.DruidPooledPreparedStatement.execute(DruidPooledPreparedStatement.java:494)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:498)

at org.apache.ibatis.logging.jdbc.PreparedStatementLogger.invoke(PreparedStatementLogger.java:59)

at com.sun.proxy.$Proxy42.execute(Unknown Source)

at org.apache.ibatis.executor.statement.PreparedStatementHandler.update(PreparedStatementHandler.java:46)

at org.apache.ibatis.executor.statement.RoutingStatementHandler.update(RoutingStatementHandler.java:74)

at org.apache.ibatis.executor.SimpleExecutor.doUpdate(SimpleExecutor.java:50)

at org.apache.ibatis.executor.BaseExecutor.update(BaseExecutor.java:117)

at org.apache.ibatis.executor.CachingExecutor.update(CachingExecutor.java:76)

at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:198)

at org.apache.ibatis.session.defaults.DefaultSqlSession.insert(DefaultSqlSession.java:185)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:498)

at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:434)

at com.sun.proxy.$Proxy20.insert(Unknown Source)

at org.mybatis.spring.SqlSessionTemplate.insert(SqlSessionTemplate.java:279)

at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:57)

at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:53)

at com.sun.proxy.$Proxy23.insert(Unknown Source)

at com.edu118.user.UserService.insertUser(UserService.java:41)

at com.edu118.action.UserAction.addUser(UserAction.java:118)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:498)

at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)

at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)

at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97)

at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)

at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)

at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)

at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)

at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)

at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)

at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)

at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)

at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)

at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)

at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)

at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)

at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)

at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)

at java.lang.Thread.run(Thread.java:745)


错误显示找不到state这个字段，我查看了一下自己写的代码，发现是jsp文件中没有添加state，于是我添加了一个隐藏字段（

）

            
            

                用户名：
                

                    
                
                
            
            

                用户密码：
                

                    
                
                
            
            

                确认密码：
                

                    
                
                
            
            

                权限设置：
                

                    
                        请选择权限
                        管理员
                        主管
                        仓储员
                        供应商
                        客户
                    
                
                
            
            

                用户信息描述：
                

                    
                
            
            

                

                    
                             
                    
                
            
        

然后重新运行，成功，当前用户可以成添加数据，数据库中user表中也添加了一条数据。