mybatis 拦截器 分页sql
项目结构基于SSM结构：已经搭建成型
项目结构如下
简单的建一个用户表 user
构建mvc三层结构
创建实体类
public class User { //实体类
private Integer id;
private String name;
private Integer age;
private Date createDate;
private String createBy;
private Date updateDate;
private String updateBy;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name == null ? null : name.trim();
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public Date getCreateDate() {
return createDate;
}
public void setCreateDate(Date createDate) {
this.createDate = createDate;
}
public String getCreateBy() {
return createBy;
}
public void setCreateBy(String createBy) {
this.createBy = createBy == null ? null : createBy.trim();
}
public Date getUpdateDate() {
return updateDate;
}
public void setUpdateDate(Date updateDate) {
this.updateDate = updateDate;
}
public String getUpdateBy() {
return updateBy;
}
public void setUpdateBy(String updateBy) {
this.updateBy = updateBy;
}
//重写一下tostring方便打印
@Override
public String toString() {
return "User{" +
"id=" + id +
", name='" + name + '\'' +
", age=" + age +
", createDate=" + createDate +
", createBy='" + createBy + '\'' +
", updateDate=" + updateDate +
", updateBy='" + updateBy + '\'' +
'}';
}
}
创建Dao层接口
public interface UserMapper { //Dao层接口
int deleteByPrimaryKey(Integer id);
int insert(User record);
int insertSelective(User record);
User selectByPrimaryKey(Integer id);
int updateByPrimaryKeySelective(User record);
int updateByPrimaryKey(User record);
}
创建dao层的xml文件
<?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.xpds.cloud.mapper.UserMapper" >
<resultMap id="BaseResultMap" type="com.xpds.cloud.entity.User" >
<id column="id" property="id" jdbcType="INTEGER" />
<result column="name" property="name" jdbcType="VARCHAR" />
<result column="age" property="age" jdbcType="INTEGER" />
<result column="create_date" property="createDate" jdbcType="TIMESTAMP" />
<result column="create_by" property="createBy" jdbcType="VARCHAR" />
<result column="update_date" property="updateDate" jdbcType="TIMESTAMP" />
<result column="uodate_by" property="uodateBy" jdbcType="VARCHAR" />
</resultMap>
<sql id="Base_Column_List" >
id, name, age, create_date, create_by, update_date, uodate_by
</sql>
<select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
select
<include refid="Base_Column_List" />
from user
where id = #{id,jdbcType=INTEGER}
</select>
<delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
delete from user
where id = #{id,jdbcType=INTEGER}
</delete>
<insert id="insert" parameterType="com.xpds.cloud.entity.User" >
insert into user (id, name, age,
create_date, create_by, update_date,
uodate_by)
values (#{id,jdbcType=INTEGER}, #{name,jdbcType=VARCHAR}, #{age,jdbcType=INTEGER},
#{createDate,jdbcType=TIMESTAMP}, #{createBy,jdbcType=VARCHAR}, #{updateDate,jdbcType=TIMESTAMP},
#{uodateBy,jdbcType=VARCHAR})
</insert>
<insert id="insertSelective" parameterType="com.xpds.cloud.entity.User" >
insert into user
<trim prefix="(" suffix=")" suffixOverrides="," >
<if test="id != null" >
id,
</if>
<if test="name != null" >
name,
</if>
<if test="age != null" >
age,
</if>
<if test="createDate != null" >
create_date,
</if>
<if test="createBy != null" >
create_by,
</if>
<if test="updateDate != null" >
update_date,
</if>
<if test="uodateBy != null" >
uodate_by,
</if>
</trim>
<trim prefix="values (" suffix=")" suffixOverrides="," >
<if test="id != null" >
#{id,jdbcType=INTEGER},
</if>
<if test="name != null" >
#{name,jdbcType=VARCHAR},
</if>
<if test="age != null" >
#{age,jdbcType=INTEGER},
</if>
<if test="createDate != null" >
#{createDate,jdbcType=TIMESTAMP},
</if>
<if test="createBy != null" >
#{createBy,jdbcType=VARCHAR},
</if>
<if test="updateDate != null" >
#{updateDate,jdbcType=TIMESTAMP},
</if>
<if test="uodateBy != null" >
#{uodateBy,jdbcType=VARCHAR},
</if>
</trim>
</insert>
<update id="updateByPrimaryKeySelective" parameterType="com.xpds.cloud.entity.User" >
update user
<set >
<if test="name != null" >
name = #{name,jdbcType=VARCHAR},
</if>
<if test="age != null" >
age = #{age,jdbcType=INTEGER},
</if>
<if test="createDate != null" >
create_date = #{createDate,jdbcType=TIMESTAMP},
</if>
<if test="createBy != null" >
create_by = #{createBy,jdbcType=VARCHAR},
</if>
<if test="updateDate != null" >
update_date = #{updateDate,jdbcType=TIMESTAMP},
</if>
<if test="uodateBy != null" >
uodate_by = #{uodateBy,jdbcType=VARCHAR},
</if>
</set>
where id = #{id,jdbcType=INTEGER}
</update>
<update id="updateByPrimaryKey" parameterType="com.xpds.cloud.entity.User" >
update user
set name = #{name,jdbcType=VARCHAR},
age = #{age,jdbcType=INTEGER},
create_date = #{createDate,jdbcType=TIMESTAMP},
create_by = #{createBy,jdbcType=VARCHAR},
update_date = #{updateDate,jdbcType=TIMESTAMP},
uodate_by = #{uodateBy,jdbcType=VARCHAR}
where id = #{id,jdbcType=INTEGER}
</update>
</mapper>
简单些一下controller 和service 打印一下查询 http://localhost:8082/user/get/id=1
查看打印结果 成功查询 出来了
然后写一个列表查询函数
controller
查询sql 
看一看数据库的数据
快看一下查询结果
创建一个分页基础类 然后用实体类进行继承
/** * 分页基础类 */ public class BaseEntity { private Integer pageSize=10; //分页行数 private Integer pageNum =1; //页码数 private Integer startNum; //启启示页码数 public Integer getPageSize() { return pageSize; } public void setPageSize(Integer pageSize) { this.pageSize = pageSize; } public Integer getPageNum() { return pageNum; } public void setPageNum(Integer pageNum) { this.pageNum = pageNum; } public Integer getStartNum() { return pageNum-1; } }
看一下传统分页写法 sql
<select id="findPage" resultMap="BaseResultMap" >
select
<include refid="Base_Column_List" />
from user limit #{startNum},#{pageSize}
</select>
但是这里我们不这么写：
先创建一个基础分页接口
修改一下我们的持久层接口
改一下我们的分页sql 不包含分页
