MyBatis存储过程、MyBatis分页、MyBatis一对多增删改查操作
发布时间:2020-12-15 08:50:46 所属栏目:Java 来源:互联网
导读:一、用到的实体类如下:Student.javapackagecom.company.entity;importjava.io.Serializable;importjava.util.Date;
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一、用到的实体类如下: Student.java
package com.company.entity;
import java.io.Serializable;
import java.util.Date;
public class Student implements Serializable{
private static final long serialVersionUID = 1L;
private int id;
private String name;
private Date birth;
private Group group;
public Group getGroup() {
return group;
}
public void setGroup(Group group) {
this.group = group;
}
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 Date getBirth() {
return birth;
}
public void setBirth(Date birth) {
this.birth = birth;
}
@Override
public String toString() {
return "Student [birth=" + birth + ",group=" + group + ",id=" + id
+ ",name=" + name + "]";
}
}
Group.Java
package com.company.entity;
import java.util.List;
public class Group {
private int id;
private String name;
private String position;
private List<Student> students;
public List<Student> getStudents() {
return students;
}
public void setStudents(List<Student> students) {
this.students = students;
}
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 String getPosition() {
return position;
}
public void setPosition(String position) {
this.position = position;
}
@Override
public String toString() {
return "Group [id=" + id + ",name=" + name + ",position=" + position
+ "]";
}
}
二、实体对应的表结构 student表: create table student( id int primary key,name varchar(20),birth date,group_id int references g_group(g_id)); g_group表: create table g_group( g_id int primary key,g_name varchar(20),g_position varchar(30)); sequence: create sequence student_id_sequence; create sequence group_id_sequence; 三、Student和Group的映射文件如下,你可以在映射文件中找到,关于MyBatis的增删改查操作,MyBatis调用存储过程,MyBatis分页以及MyBatis对一对一、多对多的处理 xml文件中都标有注释,看的时候配合下面的具体实现看,虽然有点乱 student.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.company.dao.IStudentDAO">
<!-- mybatis缓存 -->
<cache eviction="LRU" flushInterval="600000" size="1024" readOnly="false" />
<!-- sql标签用来定义一些可以被重用的sql语句或字段或片段等 -->
<sql id="studentColumns">select id,name,birth from student</sql>
<!-- 此处获得多对一的关系,但就单条记录而言却是一对一的关系,所以一对一的写法跟此相同-->
<resultMap type="Student" id="getStudentAndGroup" >
<id column="id" property="id"/>
<result column="name" property="name"/>
<result column="birth" property="birth"/>
<association property="group" column="group_id" javaType="Group">
<id column="g_id" property="id"/>
<result column="g_name" property="name"/>
<result column="g_position" property="position"/>
</association>
</resultMap>
<select id="many2one" resultMap="getStudentAndGroup" parameterType="int" >
select s.id,s.name,s.birth,s.group_id,g.g_id,g.g_name,g.g_position
from student s
left join g_group g on s.group_id = g.g_id
where s.id = #{id}
</select>
<!-- 意图是获得一个学生,并且获得该学生所属的组,跟上面的意思差不多,用association的select属性-->
<!-- 于上面的相比个人感觉上面的效率要高些,因为上面只有一条sql语句 -->
<resultMap type="Student" id="getStudentAndGroupUseSelectMap">
<id column="id" property="id"/>
<result column="name" property="name"/>
<result column="birth" property="birth"/>
<association property="group" column="group_id" javaType="Group" select="selectGroup" />
</resultMap>
<select id="getStudentAndGroupUseSelect" resultMap="getStudentAndGroupUseSelectMap" parameterType="int">
select *
from student
where id = #{id}
</select>
<select id="selectGroup" resultType="Group" parameterType="int" flushCache="false" useCache="true"><!-- 此处实用缓存 -->
select g_id as id,g_name as name,g_position as position
from g_group
where g_id = #{id}
</select>
<!-- 动态sql语句 的测试dynamic sql-->
<select id="getStudentBySomeCondition" parameterType="Student" resultType="Student">
select *
from student
<where>
<if test="id != null">
id>2
</if>
<if test="name != null">
and name like '%g%'
</if>
</where>
</select>
<!-- MyBatis调用存储过程 -->
<resultMap type="Student" id="studentMap">
<id column="id" property="id"/>
<result column="name" property="name"/>
<result column="birth" property="birth"/>
</resultMap>
<select id="getAllUser" statementType="CALLABLE" >
{call get_all_student(#{students,mode=OUT,jdbcType=CURSOR,javaType=ResultSet,resultMap=studentMap} )}
</select>
<!-- MyBatis向student表中插入一条数据 -->
<insert id="add" parameterType="Student" keyColumn="id">
<selectKey keyProperty="id" order="BEFORE" resultType="int">
select stu_id_sequence.nextval from dual
</selectKey>
insert into student(id,birth) values(#{id},#{name},#{birth})
</insert>
<!-- 根据id获得学生的信息 -->
<select id="getById" parameterType="int" resultType="Student">
<include refid="studentColumns"/> where id=#{id}
</select>
<!-- 此处的实现方法是一个分页的原型,请查看IStudentDAOImpl.java中的调用方法 -->
<select id="getAllStudent" resultMap="studentMap">
<include refid="studentColumns"/> order by id<!--此处是引用了上面预定义好的sql语句-->
</select>
</mapper>
以上所述是小编给大家介绍的MyBatis存储过程、MyBatis分页、MyBatis一对多增删改查操作,希望对大家有所帮助,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对编程小技巧网站的支持! (编辑:哈尔滨站长网) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |
