MyBatis笔记----mybatis分页


mybatis版本3.4以下

结构

spring-mvc.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://www.springframework.org/schema/beans"
        xmlns:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-4.3.xsd">
<!--   自动扫描加载注解的包 -->
<context:component-scan base-package="com.ij34.bean"/>
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/view/"></property>
<property name="suffix" value=".jsp" ></property>
</bean>

</beans>

com.ij34.mybatis

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="
            http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-4.3.xsd"
            default-autowire="byName" default-lazy-init="false">
    <!-- Showcase‘s CustomFreemarkerManager example -->
  <bean id="dataSource" class="org.apache.commons.dbcp2.BasicDataSource">
     <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
     <property name="url" value="jdbc:mysql://localhost:3306/mybatis"></property>
     <property name="username" value="root"></property>
     <property name="password" value="123456"></property>
  </bean>
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
      <property name="dataSource" ref="dataSource" />
    </bean>
  <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
      <property name="dataSource" ref="dataSource"></property>
      <property name="configLocation" value="classpath:com/ij34/mybatis/mybatis-config.xml"></property>
      <property name="mapperLocations" value="classpath:com/ij34/mybatis/UserMapper.xml"></property>
  </bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <property name="basePackage" value="com.ij34.model"></property>
    <property name="sqlSessionFactory" ref="sqlSessionFactory" />
</bean>
</beans>

mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
  PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<typeAliases>
<typeAlias type="com.ij34.model.Article" alias="Article"/>
<typeAlias type="com.ij34.model.User" alias="User"/>
<typeAlias type="com.ij34.pages.PageInfo" alias="PageInfo"/>
</typeAliases>
  <plugins>
        <plugin interceptor="com.ij34.pages.PagePlugin">
            <property name="dialect" value="mysql" />
            <property name="pageSqlId" value=".*ListPage.*" />
        </plugin>
    </plugins>
</configuration>

UserMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
  PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

  <mapper  namespace="com.ij34.model.UserMapper">
<resultMap type="Article" id="resultAticleList">
  <id property="id" column="aid"/>
  <result property="title" column="title"/>
  <result property="content" column="content"/>
  <association property="user" javaType="User">
  <id property="id" column="id"/>
  <result property="name" column="name"/>
  <result property="age" column="age"/>
  </association>
  </resultMap>
   <select id="selectarticle" parameterType="int" resultMap="resultAticleList">
  select users.id,users.name,users.age,article.id aid,article.title,article.content from users,article
  where users.id=article.userid and users.id=#{id}
  </select>

  <select id="ListPage" resultMap="resultAticleList">
  select users.id,users.name,users.age,article.id aid,article.title,article.content from users,article
  where users.id=article.userid and users.id=#{userid}
  </select>

  </mapper>

com.ij34.model

User.java

package com.ij34.model;

public class User {
  private int id;
  private String name;
  private int age;

  public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public int getAge() {
    return age;
}

public void setAge(int age) {
    this.age = age;
}
public String toString() {
    return "User [id=" + id + ", name=" + name + ", age=" + age + "]";
}

}

Article.java

package com.ij34.model;

public class Article {
  private int id;
  private User user;
  private String title;
  private String content;

public String getContent() {
    return content;
}
public void setContent(String content) {
    this.content = content;
}
public int getId() {
    return id;
}
public void setId(int id) {
    this.id = id;
}
public User getUser() {
    return user;
}
public void setUser(User user) {
    this.user = user;
}
public String getTitle() {
    return title;
}
public void setTitle(String title) {
    this.title = title;
}

}

UserMapper.java

package com.ij34.model;

import java.util.List;

import org.apache.ibatis.annotations.Param;

import com.ij34.pages.PageInfo;

public interface UserMapper {

    public List<Article> selectarticle(int id);
    public List<Article> ListPage(@Param("page") PageInfo page,@Param("userid") int userid);
}

com.ij34.pages

参考网上的分页插件

PageInfo.java

package com.ij34.pages;

import java.io.Serializable;

public class PageInfo implements Serializable {

    private static final long serialVersionUID = 587754556498974978L;

    //pagesize ，每一页显示多少
    private int showCount = 9;
    //总页数
    private int totalPage;
    //总记录数
    private int totalResult;
    //当前页数
    private int currentPage;
    //当前显示到的ID, 在mysql limit 中就是第一个参数.
    private int currentResult;
    private String sortField;
    private String order;

    public int getShowCount() {
        return showCount;
    }
    public void setShowCount(int showCount) {
        this.showCount = showCount;
    }
    public int getTotalPage() {
        return totalPage;
    }
    public void setTotalPage(int totalPage) {
        this.totalPage = totalPage;
    }
    public int getTotalResult() {
        return totalResult;
    }
    public void setTotalResult(int totalResult) {
        this.totalResult = totalResult;
    }
    public int getCurrentPage() {
        return currentPage;
    }
    public void setCurrentPage(int currentPage) {
        this.currentPage = currentPage;
    }
    public int getCurrentResult() {
        return currentResult;
    }
    public void setCurrentResult(int currentResult) {
        this.currentResult = currentResult;
    }
    public String getSortField() {
        return sortField;
    }
    public void setSortField(String sortField) {
        this.sortField = sortField;
    }
    public String getOrder() {
        return order;
    }
    public void setOrder(String order) {
        this.order = order;
    }

}

PagePlugin.java

@Intercepts({ @Signature(type = StatementHandler.class, method = "prepare", args = { Connection.class }) })

要用3.4以下版本，可以参考官方

package com.ij34.pages;

import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;
import java.util.Properties;

import javax.xml.bind.PropertyException;

import org.apache.ibatis.executor.ErrorContext;
import org.apache.ibatis.executor.ExecutorException;
import org.apache.ibatis.executor.statement.BaseStatementHandler;
import org.apache.ibatis.executor.statement.RoutingStatementHandler;
import org.apache.ibatis.executor.statement.StatementHandler;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.ParameterMapping;
import org.apache.ibatis.mapping.ParameterMode;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.plugin.Intercepts;
import org.apache.ibatis.plugin.Invocation;
import org.apache.ibatis.plugin.Plugin;
import org.apache.ibatis.plugin.Signature;
import org.apache.ibatis.reflection.MetaObject;
import org.apache.ibatis.reflection.property.PropertyTokenizer;
import org.apache.ibatis.scripting.xmltags.ForEachSqlNode;
import org.apache.ibatis.session.Configuration;

import org.apache.ibatis.type.TypeHandler;
import org.apache.ibatis.type.TypeHandlerRegistry;

@Intercepts({ @Signature(type = StatementHandler.class, method = "prepare", args = { Connection.class }) })
public class PagePlugin implements Interceptor {

    private static String dialect = "";
    private static String pageSqlId = "";

    @SuppressWarnings("unchecked")
    public Object intercept(Invocation ivk) throws Throwable {

        if (ivk.getTarget() instanceof RoutingStatementHandler) {
            RoutingStatementHandler statementHandler = (RoutingStatementHandler) ivk
                    .getTarget();
            BaseStatementHandler delegate = (BaseStatementHandler) ReflectHelper
                    .getValueByFieldName(statementHandler, "delegate");
            MappedStatement mappedStatement = (MappedStatement) ReflectHelper
                    .getValueByFieldName(delegate, "mappedStatement");

            if (mappedStatement.getId().matches(pageSqlId)) {
                BoundSql boundSql = delegate.getBoundSql();
                Object parameterObject = boundSql.getParameterObject();
                if (parameterObject == null) {
                    throw new NullPointerException("parameterObject error");
                } else {
                    Connection connection = (Connection) ivk.getArgs()[0];
                    String sql = boundSql.getSql();
                    String countSql = "select count(0) from (" + sql + ") myCount";
                    System.out.println("总数sql 语句:"+countSql);
                    PreparedStatement countStmt = connection
                            .prepareStatement(countSql);
                    BoundSql countBS = new BoundSql(
                            mappedStatement.getConfiguration(), countSql,
                            boundSql.getParameterMappings(), parameterObject);
                    setParameters(countStmt, mappedStatement, countBS,
                            parameterObject);
                    ResultSet rs = countStmt.executeQuery();
                    int count = 0;
                    if (rs.next()) {
                        count = rs.getInt(1);
                    }
                    rs.close();
                    countStmt.close();

                    PageInfo page = null;
                    if (parameterObject instanceof PageInfo) {
                        page = (PageInfo) parameterObject;
                        page.setTotalResult(count);
                    } else if(parameterObject instanceof Map){
                        Map<String, Object> map = (Map<String, Object>)parameterObject;
                        page = (PageInfo)map.get("page");
                        if(page == null)
                            page = new PageInfo();
                        page.setTotalResult(count);
                    }else {
                        Field pageField = ReflectHelper.getFieldByFieldName(
                                parameterObject, "page");
                        if (pageField != null) {
                            page = (PageInfo) ReflectHelper.getValueByFieldName(
                                    parameterObject, "page");
                            if (page == null)
                                page = new PageInfo();
                            page.setTotalResult(count);
                            ReflectHelper.setValueByFieldName(parameterObject,
                                    "page", page);
                        } else {
                            throw new NoSuchFieldException(parameterObject
                                    .getClass().getName());
                        }
                    }
                    String pageSql = generatePageSql(sql, page);
                    System.out.println("page sql:"+pageSql);
                    ReflectHelper.setValueByFieldName(boundSql, "sql", pageSql);
                }
            }
        }
        return ivk.proceed();
    }

    private void setParameters(PreparedStatement ps,
            MappedStatement mappedStatement, BoundSql boundSql,
            Object parameterObject) throws SQLException {
        ErrorContext.instance().activity("setting parameters")
                .object(mappedStatement.getParameterMap().getId());
        List<ParameterMapping> parameterMappings = boundSql
                .getParameterMappings();
        if (parameterMappings != null) {
            Configuration configuration = mappedStatement.getConfiguration();
            TypeHandlerRegistry typeHandlerRegistry = configuration
                    .getTypeHandlerRegistry();
            MetaObject metaObject = parameterObject == null ? null
                    : configuration.newMetaObject(parameterObject);
            for (int i = 0; i < parameterMappings.size(); i++) {
                ParameterMapping parameterMapping = parameterMappings.get(i);
                if (parameterMapping.getMode() != ParameterMode.OUT) {
                    Object value;
                    String propertyName = parameterMapping.getProperty();
                    PropertyTokenizer prop = new PropertyTokenizer(propertyName);
                    if (parameterObject == null) {
                        value = null;
                    } else if (typeHandlerRegistry
                            .hasTypeHandler(parameterObject.getClass())) {
                        value = parameterObject;
                    } else if (boundSql.hasAdditionalParameter(propertyName)) {
                        value = boundSql.getAdditionalParameter(propertyName);
                    } else if (propertyName
                            .startsWith(ForEachSqlNode.ITEM_PREFIX)
                            && boundSql.hasAdditionalParameter(prop.getName())) {
                        value = boundSql.getAdditionalParameter(prop.getName());
                        if (value != null) {
                            value = configuration.newMetaObject(value)
                                    .getValue(
                                            propertyName.substring(prop
                                                    .getName().length()));
                        }
                    } else {
                        value = metaObject == null ? null : metaObject
                                .getValue(propertyName);
                    }
                    TypeHandler typeHandler = parameterMapping.getTypeHandler();
                    if (typeHandler == null) {
                        throw new ExecutorException(
                                "There was no TypeHandler found for parameter "
                                        + propertyName + " of statement "
                                        + mappedStatement.getId());
                    }
                    typeHandler.setParameter(ps, i + 1, value,
                            parameterMapping.getJdbcType());
                }
            }
        }
    }

    private String generatePageSql(String sql, PageInfo page) {
        if (page != null && (dialect !=null || !dialect.equals(""))) {
            StringBuffer pageSql = new StringBuffer();
            if ("mysql".equals(dialect)) {
                pageSql.append(sql);
                pageSql.append(" limit " + page.getCurrentResult() + ","
                        + page.getShowCount());
            } else if ("oracle".equals(dialect)) {
                pageSql.append("select * from (select tmp_tb.*,ROWNUM row_id from (");
                pageSql.append(sql);
                pageSql.append(")  tmp_tb where ROWNUM<=");
                pageSql.append(page.getCurrentResult() + page.getShowCount());
                pageSql.append(") where row_id>");
                pageSql.append(page.getCurrentResult());
            }
            return pageSql.toString();
        } else {
            return sql;
        }
    }

    public Object plugin(Object arg0) {
        // TODO Auto-generated method stub
        return Plugin.wrap(arg0, this);
    }

    public void setProperties(Properties p) {
        dialect = p.getProperty("dialect");
        if (dialect ==null || dialect.equals("")) {
            try {
                throw new PropertyException("dialect property is not found!");
            } catch (PropertyException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        pageSqlId = p.getProperty("pageSqlId");
        if (dialect ==null || dialect.equals("")) {
            try {
                throw new PropertyException("pageSqlId property is not found!");
            } catch (PropertyException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

}

ReflectHelper.java

package com.ij34.pages;

import java.lang.reflect.Field;

public class ReflectHelper {
    public static Field getFieldByFieldName(Object obj, String fieldName) {
        for (Class<?> superClass = obj.getClass(); superClass != Object.class; superClass = superClass
                .getSuperclass()) {
            try {
                return superClass.getDeclaredField(fieldName);
            } catch (NoSuchFieldException e) {
            }
        }
        return null;
    }  

    public static Object getValueByFieldName(Object obj, String fieldName)
            throws SecurityException, NoSuchFieldException,
            IllegalArgumentException, IllegalAccessException {
        Field field = getFieldByFieldName(obj, fieldName);
        Object value = null;
        if(field!=null){
            if (field.isAccessible()) {
                value = field.get(obj);
            } else {
                field.setAccessible(true);
                value = field.get(obj);
                field.setAccessible(false);
            }
        }
        return value;
    }  

    public static void setValueByFieldName(Object obj, String fieldName,
            Object value) throws SecurityException, NoSuchFieldException,
            IllegalArgumentException, IllegalAccessException {
        Field field = obj.getClass().getDeclaredField(fieldName);
        if (field.isAccessible()) {
            field.set(obj, value);
        } else {
            field.setAccessible(true);
            field.set(obj, value);
            field.setAccessible(false);
        }
    }  

}

com.ij34.bean

package com.ij34.bean;

import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

import com.ij34.model.*;
import com.ij34.pages.PageInfo;

@Controller
@RequestMapping("/article")
public class Test {
    @Autowired
    UserMapper mapper;

    @RequestMapping("/list")
    public ModelAndView listall(HttpServletRequest request,HttpServletResponse response){
        List<Article> articles=mapper.selectarticle(1);
        //制定视图，也就是list.jsp
        ModelAndView mav=new ModelAndView("list");
        mav.addObject("articles",articles);
        return mav;
    }

  @RequestMapping("/pagelist")
    public ModelAndView pageList(HttpServletRequest request,HttpServletResponse response){
        int currentPage = request.getParameter("page")==null?1:Integer.parseInt(request.getParameter("page"));
        int pageSize = 9;
        if (currentPage<=1){
            currentPage =1;
        }
        int currentResult = (currentPage-1) * pageSize;

        System.out.println(request.getRequestURI());
        System.out.println(request.getQueryString());

        PageInfo page = new PageInfo();
        page.setShowCount(pageSize);
        page.setCurrentResult(currentResult);
        List<Article> articles=mapper.ListPage(page,1);

        System.out.println(page);

        int totalCount = page.getTotalResult();

        int lastPage=0;
        if (totalCount % pageSize==0){
            lastPage = totalCount % pageSize;
        }
        else{
            lastPage =1+ totalCount / pageSize;
        }

        if (currentPage>=lastPage){
            currentPage =lastPage;
        }

        String pageStr = "";
        pageStr=String.format("<a href=\"%s\">上一页</a>&nbsp;&nbsp;&nbsp;&nbsp;<a href=\"%s\">下一页</a>",
                        request.getRequestURI()+"?page="+(currentPage-1),request.getRequestURI()+"?page="+(currentPage+1) );

        //制定视图，也就是list.jsp
        ModelAndView mav=new ModelAndView("list");
        mav.addObject("articles",articles);
        mav.addObject("pageStr",pageStr);
        return mav;
    }
/*  public ModelAndView show(){//@RequestParam  请求参数
     List<Article> articles=mapper.selectarticle(1);
     ModelAndView mav=new ModelAndView("list");
     mav.addObject("articles", articles);
    return mav;

  }*/
}

WebContent

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>mybatis_springmvc</display-name>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:com/ij34/mybatis/applicationContext.xml</param-value>
  </context-param>
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  <listener>
    <listener-class>
            org.springframework.web.context.ContextCleanupListener</listener-class>
  </listener>
  <servlet>
    <servlet-name>springDispatcherServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:spring-mvc.xml</param-value>
    </init-param>
  </servlet>
  <servlet-mapping>
    <servlet-name>springDispatcherServlet</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>
  <filter>
    <filter-name>characterEncodingfilter</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <init-param>
      <param-name>encoding</param-name>
      <param-value>utf8</param-value>
    </init-param>
    <init-param>
      <param-name>forceEncoding</param-name>
      <param-value>true</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>characterEncodingfilter</filter-name>
    <url-pattern>*</url-pattern>
  </filter-mapping>
</web-app>

index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
   <a href="article/list">不分页测试</a><br /><p />
   <a href="article/pagelist">分页测试</a>
</body>
</html>

list.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<table>
<c:forEach var="article" items="${articles}">
<tr><td>${article.id} |</td><td> ${article.title}|</td><td> ${article.content}|</td><td>${article.user}</td> </tr>
</c:forEach>
</table>
<h4>${pageStr}</h4>
</body>
</html>

结果

时间： 2024-11-12 10:07:27

MyBatis笔记----mybatis分页的相关文章

MyBatis笔记----MyBatis 入门经典的两个例子： XML 定义与注解定义

----致敬MyBatis官方开放文档让大家翻译,不用看书直接看文档就行了,mybatis的中文文档还需要完备的地方 简介 什么是 MyBatis ? MyBatis 是支持定制化 SQL.存储过程以及高级映射的优秀的持久层框架.MyBatis 避免了几乎所有的 JDBC 代码和手动设置参数以及获取结果集.MyBatis 可以对配置和原生Map使用简单的 XML 或注解,将接口和 Java 的 POJOs(Plain Old Java Objects,普通的 Java对象)映射成数据库中的记录.

MyBatis 杂项（分页，缓存，处理BLOB\CLOB数据）

1.处理CLOB,BLOB数据 oracle中的 clob:clob blob:blobmysql中的 clob:longtext blob:longblob 2.传入多个输入参数,mybatis自带的param属性(但是不经常用,我们用map就足够了) 3.MyBatis分页 逻辑分页:将数据全部取出先放到内存中,之后在内存中进行分页,性能不好.不推荐使用 物理分页:通过语句进行分页. 4.MyBatis缓存 MyBatis默认情况下:MyBatis默认使用一级缓存,即同一个SqlSessio

Mybatis Generator实现分页功能

Mybatis Generator实现分页功能 分类: IBATIS2013-07-17 17:03 882人阅读 评论(1) 收藏 举报 mybatisibatisgeneratorpage分页 众所周知,Mybatis本身没有提供基于数据库方言的分页功能,而是基于JDBC的游标分页,很容易出现性能问题.网上有很多分页的解决方案,不外乎是基于Mybatis本机的插件机制,通过拦截Sql做分页.但是在像Oracle这样的数据库上,拦截器生成的Sql语句没有变量绑定,而且每次语句的都要去拦截,感觉

MyBatis笔记----Mybatis3.4.2与spring4整合：增删查改

结构图 刚之前没什么区别,多了一个applicationContext.xml 包图 由于之前出了一点错误,有些包可能多加上了 数据库图 model User.java package com.ij34.model; public class User { private int id; private String name; private int age; public int getId() { return id; } public void setId(int id) { this.

Mybatis笔记

1.ibatis是mybatis的前身. 2.mybatis比hibernate灵活,性能也比hibernate好,而且也比较轻量级. 3.什么是mybatis: MyBatis是支持普通SQL查询,存储过程和高级映射的优秀持久层框架. MyBatis消除了几乎所有的JDBC代码和参数的手工设置以及结果集的检索. MyBatis使用简单的XML或注解用于配置和原始映射, 将接口和Java的POJOs(Plan Old Java Objects,普通的Java对象) 映射成 数据库中的记录. 4.

Mybatis使用之分页

Mybatis使用之分页 一:简介 注:示例基于mysql数据库.Oracle可以自行测试.   使用Mybatis分页主要有两种方式.一种是将分页参数传递到配置文件中.在写sql的时候就做分页.另一种是使用Mybatis的拦截器拦截需要分页的sql语句.重新组装成具有分页功能的sql语句. 分页查询的关键在于查询时需要告诉数据库从第几条开始取.取多少条记录.也就是常用到Page对象(一般是方便传递参数.自己构建的实体类)的pageNumer.pageSize两个主要参数.至于Page对象的总记

Mybatis最入门---分页查询（拦截器分页原理及实现）

[一步是咫尺,一步即天涯] 前文,我们演示了物理分页的Sql实现方式,这种方式使得我们每次在编写查询服务时,不断的重复造轮子.这样的代码实现方式就显得十分的笨拙了.本文是Mybatis分页查询的最后一片内容,我们将介绍基于拦截器的,精巧的实现方式.在阅读这篇文章之前,强烈建议各位看官能够先阅读上文.这样就能对下文我们提及的各种对象及他们之间的关系有一个清晰的关系.好了,废话不多讲,开始我们的正文部分吧. 准备工作: a.操作系统 :win7 x64 b.基本软件:MySQL,Mybatis,SQ

SpringBoot+Mybatis配置Pagehelper分页插件实现自动分页

SpringBoot+Mybatis配置Pagehelper分页插件实现自动分页 **SpringBoot+Mybatis使用Pagehelper分页插件自动分页,非常好用,不用在自己去计算和组装了.全部自动实现. 话不多说,直接上代码: 第一步pom文件配置添加jar: <!-- mybatis的分页插件 --> <dependency> <groupId>com.github.pagehelper</groupId> <artifactId>

小白的springboot之路（十五）、mybatis的PageHelper分页插件使用

0.前言 用mybatis,那么分页必不可少,基本都是用PageHelper这个分页插件,好用方便: 1.实现 1.1.添加依赖: <!-- 3.集成 mybatis pagehelper--> <dependency> <groupId>com.github.pagehelper</groupId> <artifactId>pagehelper-spring-boot-starter</artifactId> <version