MyBatis 分页插件PageHelper 后台报错
今天遇到一个问题,使用MyBatis 分页插件PageHelper 进行排序分页后,能正常返回正确的结果,但后台却一直在报错 net.sf.jsqlparser.parser.ParseException
(不排序的话,没报什么错,我也还没找到原因)
具体错误信息如下所示:
net.sf.jsqlparser.JSQLParserException
at net.sf.jsqlparser.parser.CCJSqlParserUtil.parse(CCJSqlParserUtil.java:56)
at com.github.pagehelper.parser.OrderByParser.converToOrderBySql(OrderByParser.java:51)
at com.github.pagehelper.dialect.AbstractHelperDialect.getPageSql(AbstractHelperDialect.java:176)
at com.github.pagehelper.PageHelper.getPageSql(PageHelper.java:97)
at com.github.pagehelper.PageInterceptor.intercept(PageInterceptor.java:129)
at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:61)
at com.sun.proxy.$Proxy130.query(Unknown Source)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:147)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:140)
at sun.reflect.GeneratedMethodAccessor165.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:426)
at com.sun.proxy.$Proxy82.selectList(Unknown Source)
at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:223)
at org.apache.ibatis.binding.MapperMethod.executeForMany(MapperMethod.java:147)
at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:80)
at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:57)
at com.sun.proxy.$Proxy100.selectByCondition(Unknown Source)
// 分页接口的具体设置、实现地方,从这里就可以确定是执行分页时出现的错
at *.*.*.*.BaseService.findByCondition(BaseService.java:99)
at *.*.*.*.service.impl.*ServiceImpl.queryPageByProjectId(*ServiceImpl.java:121) 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.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:343)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:197)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:294)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
at com.sun.proxy.$Proxy101.queryPageByProjectId(Unknown Source)
// 分页接口调用的地方
at *.*.*.*.controller.*Controller.list(*Controller.java:66) 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.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:877)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at com.alibaba.druid.support.http.WebStatFilter.doFilter(WebStatFilter.java:123)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1468)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
Caused by: net.sf.jsqlparser.parser.ParseException: Encountered " "ENABLE" "enable "" at line 1, column 92.
Was expecting one of:
"DO" ...
"ANY" ...
"KEY" ...
......
"COMMIT" ...
"PRECISION" ...
"INSERT" ... at net.sf.jsqlparser.parser.CCJSqlParser.generateParseException(CCJSqlParser.java:16395)
at net.sf.jsqlparser.parser.CCJSqlParser.jj_consume_token(CCJSqlParser.java:16248)
at net.sf.jsqlparser.parser.CCJSqlParser.SelectItem(CCJSqlParser.java:2960)
at net.sf.jsqlparser.parser.CCJSqlParser.SelectItemsList(CCJSqlParser.java:2818)
at net.sf.jsqlparser.parser.CCJSqlParser.PlainSelect(CCJSqlParser.java:2431)
at net.sf.jsqlparser.parser.CCJSqlParser.SetOperationList(CCJSqlParser.java:2579)
at net.sf.jsqlparser.parser.CCJSqlParser.SelectBody(CCJSqlParser.java:2336)
at net.sf.jsqlparser.parser.CCJSqlParser.Select(CCJSqlParser.java:2328)
at net.sf.jsqlparser.parser.CCJSqlParser.SingleStatement(CCJSqlParser.java:129)
at net.sf.jsqlparser.parser.CCJSqlParser.Statement(CCJSqlParser.java:80)
at net.sf.jsqlparser.parser.CCJSqlParserUtil.parse(CCJSqlParserUtil.java:54)
at com.github.pagehelper.parser.OrderByParser.converToOrderBySql(OrderByParser.java:51)
at com.github.pagehelper.dialect.AbstractHelperDialect.getPageSql(AbstractHelperDialect.java:176)
at com.github.pagehelper.PageHelper.getPageSql(PageHelper.java:97)
at com.github.pagehelper.PageInterceptor.intercept(PageInterceptor.java:129)
at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:61)
at com.sun.proxy.$Proxy130.query(Unknown Source)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:147)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:140)
at sun.reflect.GeneratedMethodAccessor165.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:426)
at com.sun.proxy.$Proxy82.selectList(Unknown Source)
at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:223)
at org.apache.ibatis.binding.MapperMethod.executeForMany(MapperMethod.java:147)
at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:80)
at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:57)
at com.sun.proxy.$Proxy100.selectByCondition(Unknown Source)
at com.seekway.cloud.core.BaseService.findByCondition(BaseService.java:99)
at com.seekway.cloud.api.service.impl.TimeCtrlServiceImpl.queryPageByProjectId(TimeCtrlServiceImpl.java:121)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:343)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:197)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:294)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
at com.sun.proxy.$Proxy101.queryPageByProjectId(Unknown Source)
at com.seekway.cloud.api.controller.TimeCtrlController.list(TimeCtrlController.java:66)
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.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:877)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at com.alibaba.druid.support.http.WebStatFilter.doFilter(WebStatFilter.java:123)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1468)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
仔细看,发现有可能是 字段名名称enable 与 数据库关键字冲突
改后发现没报错了,真是丢人了,设置字段名不规范
共同学习,共同进步,若有补充,欢迎指出,谢谢!
MyBatis 分页插件PageHelper 后台报错的更多相关文章
- Mybatis学习---Mybatis分页插件 - PageHelper
1. Mybatis分页插件 - PageHelper说明 如果你也在用Mybatis,建议尝试该分页插件,这个一定是最方便使用的分页插件. 该插件目前支持Oracle,Mysql,MariaDB,S ...
- Mybatis分页插件PageHelper的实现
Mybatis分页插件PageHelper的实现 前言 分页这个概念在做web网站的时候很多都会碰到 说它简单吧 其实也简单 小型的网站,完全可以自己写一个,首先查出数据库总条数,然后按照分页大小分为 ...
- (转)淘淘商城系列——MyBatis分页插件(PageHelper)的使用以及商品列表展示
http://blog.csdn.net/yerenyuan_pku/article/details/72774381 上文我们实现了展示后台页面的功能,而本文我们实现的主要功能是展示商品列表,大家要 ...
- Mybatis分页插件PageHelper的配置和使用方法
Mybatis分页插件PageHelper的配置和使用方法 前言 在web开发过程中涉及到表格时,例如dataTable,就会产生分页的需求,通常我们将分页方式分为两种:前端分页和后端分页. 前端分 ...
- Mybatis分页插件PageHelper使用
一. Mybatis分页插件PageHelper使用 1.不使用插件如何分页: 使用mybatis实现: 1)接口: List<Student> selectStudent(Map< ...
- Java SSM框架之MyBatis3(三)Mybatis分页插件PageHelper
引言 对于使用Mybatis时,最头痛的就是写分页,需要先写一个查询count的select语句,然后再写一个真正分页查询的语句,当查询条件多了之后,会发现真不想花双倍的时间写count和select ...
- 基于Mybatis分页插件PageHelper
基于Mybatis分页插件PageHelper 1.分页插件使用 1.POM依赖 PageHelper的依赖如下.需要新的版本可以去maven上自行选择 <!-- PageHelper 插件分页 ...
- Mybatis分页插件-PageHelper的使用
转载:http://blog.csdn.net/u012728960/article/details/50791343 Mybatis分页插件-PageHelper的使用 怎样配置mybatis这里就 ...
- springmvc mybatis 分页插件 pagehelper
springmvc mybatis 分页插件 pagehelper 下载地址:pagehelper 4.2.1 , jsqlparser 0.9.5 https://github.com/pagehe ...
随机推荐
- 【POJ - 3614】Sunscreen (优先队列)
Sunscreen Descriptions C (1 ≤ C ≤ 2500) 头奶牛在海滩边晒太阳,要避免在日光浴时产生难看的灼伤,每头奶牛必须用防晒霜覆盖它的皮肤.第 i 头奶牛有一个最小和最大 ...
- Linux 操作系统常用命令
常用命令详解 ls 常用选项: -a:列出所有文件,包括以.为开头的隐藏文件. -d ; 列出目录本身,并不包含目录里的内容. -h:和-l一起使用,文件大小容易阅读.文件的实际大小 ls -d/ro ...
- K/3 Cloud 中FID和FMasterID的区别
经常会用到,例如物料在多组织情况下. 例如一个物料分配不同组织后,内码FID肯定是不同的,但FMaterId还是一样的,因为是用一个物料. FMASTERID是和物料编码对应的内码,即一个物料编码对应 ...
- nRF5 SDK Bootloader and DFU moudles(1)
在嵌入式操作系统中,BootLoader是在操作系统内核运行之前运行.可以初始化硬件设备.建立内存空间映射图,从而将系统的软硬件环境带到一个合适状态,以便为最终调用操作系统内核准备好正确的环境. 在嵌 ...
- SpringMVC 零配置 无web.xml
对SpringMVC启动流程的讲解 https://www.cnblogs.com/beiyan/p/5942741.html 与SpringMVC的整合 https://hanqunfeng.ite ...
- JS 获取当前定位
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8&quo ...
- 第六周课程总结&java实验报告四
第六周课程总结: 一.instanceof关键字 1.作用:在Java中可以使用instanceof关键字判断一个对象到底是哪个类的实例. 2.格式:对象 instanceof 类 -> 返回b ...
- 重载(overload)和重写(override)的区别
方法的重载和重写都是实现多态的方式,区别在于前者实现的是编译时的多态性,而后者实现的是运行时的多态性. 重载发生在一个类中,同名的方法如果有不同的参数列表(参数类型不同.参数个数不同或者二者都不同)则 ...
- 查看Oracle索引是否被使用或者有效
第一步: explain plan for select * from T_USER where OPEN_ID='12345'; 第二步: select * from table(dbms_xpla ...
- C++中的bool类型
1.C++中的布尔类型 (1)C++在C语言的基础类型系统之上增加了bool: 1)C语言中,没有bool类型存在,往往都是用整型代替bool类型,常用0表示假,1表示真: 2)bool本来就有这样的 ...