1. 批处理 插入
非常多时候都涉及到一系列数据的插入，通过mybatis的动态sql语句可以非常好的解决问题。当然。oracle已经提供了批插入的语句：
insert into students
select id,name ,email ,sdate from dual union
select id,name ,email ,sdate from dual union
select id,name ,email ,sdate from dual 利用mybatis动态sql语言的写法：
<!-- 集合 有集合类型 collection 可以指定 parameterType="list" -->
<!-- 数组没有 array 的參数类型 collection="array" parameterType 指定是数组里面存放的数据类型 -->
<insert id="batchInsertStudents" parameterType="list">
insert into students
<foreach collection="list" separator=" union " item="stus">
select #{stus.id},#{stus.name},#{stus.email},#{stus.sdate} from dual
</foreach>
</insert>以下看測试：
/**
* 批处理： 插入一组数据
*/
@Test
public void TestbatchInsertStudents(){
List<Student> stus=Arrays.asList(new Student[]{
new Student("Rindy_1",9770,"15211433541013",new Date()),
new Student("Rindy_2",97710,"1521143546392@163.com",new Date()),
new Student("Rindy_3",97720,"152114743366658",new Date()),
new Student("Rindy_4",97730,"1527395357437",new Date()),
new Student("Rindy_5",97740,"132126835435644",new Date()),
new Student("Rindy_6",97750,"152114524322140",new Date()),
new Student("Rindy_7",97760,"15873242923860",new Date()),
new Student("Rindy_8",97770,"15096242043460",new Date())
});
int rows=stum.batchInsertStudents( stus );
System.out.println( rows );
assertEquals(rows,8);
}測试成功
批量删除：
<delete id="deleteStuById" parameterType="int">
delete from students where stud_id= #{id}
</delete>測试成功
批量更新比較麻烦，我们先来回想一下 oracle的更新：
UPDATE 表名 set 列名 = 新值[, 列名 = 新值[…]] [WHERE condition_expression];
參数多组。批量操作可採用 case when then语句实现
<!-- 批处理： update students set xxx where id -->
<update id="batchUpdateStudents02" parameterType="list">
update students
<set>
<foreach collection="list" item="stus" open="name = case " close="end,">
when stud_id=#{stus.id} then #{stus.name}
</foreach>
<foreach collection="list" item="stus" open="email = case " close="end,">
when stud_id=#{stus.id} then #{stus.email}
</foreach>
<foreach collection="list" item="stus" open="sdate = case " close="end,">
<!-- 容错处理。当属性值为空的时候。不更新 -->
<if test=" #{stus.sdate} !=null ">
when stud_id=#{stus.id} then #{stus.sdate}
</if>
</foreach>
</set>
<foreach collection="list" open="where stud_id in(" separator="," item="stus" close=")">
#{stus.id}
</foreach>
</update>測试：
/**
* 批处理： 更新一组数据
*/
@Test
public void TestbatchUpdateStudents(){
List<Student> stus=Arrays.asList(new Student[]{
new Student("Rindy_1_update",9770,"15211423431013_update",new Date()),
new Student("Rindy_2_update",97710,"15211433446392@163.com",new Date()),
new Student("Rindy_3_update",97720,"1524321231476658_update",new Date()),
new Student("Rindy_4_update",97730,"1527395324327437_update",new Date()),
new Student("Rindy_5_update",97740,"13212268235644_update",new Date()),
new Student("Rindy_6_update",97750,"152114522432140_update",new Date()),
new Student("Rindy_7_update",97760,"1587233922433860_update",new Date()),
new Student("Rindy_8_update",97770,"1502496032443460_update",new Date())
});
int rows=stum.batchUpdateStudents02( stus );
System.out.println( rows );
assertEquals(rows,8);
}測试结果
以下是是本次案例的辅助代码
- 数据库脚本
DROP TABLE STUDENTS;
drop sequence seq_stu_id;
CREATE TABLE STUDENTS
(
stud_id integer PRIMARY KEY,
name varchar2(50) NOT NULL,
email varchar2(50) ,
sdate date
);
create sequence seq_stu_id ;
insert into students(name,email,dob) values('Student1','student1@gmail.com', to_date('1983-06-25', 'yyyy-MM-dd');
insert into students(name,email,dob) values('Student2','student2@gmail.com', to_date('1985-06-25', 'yyyy-MM-dd');
2.java entity
package com.rindy.maven.entity;
import java.util.Date;
public class Student {
private String name;
private Integer id;
private String email;
private Date sdate;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Date getSdate() {
return sdate;
}
public void setSdate(Date sdate) {
this.sdate = sdate;
}
public Student(String name, Integer id, String email, Date sdate) {
super();
this.name = name;
this.id = id;
this.email = email;
this.sdate = sdate;
}
public Student() {
super();
}
public Student(String name, String email, Date sdate) {
super();
this.name = name;
this.email = email;
this.sdate = sdate;
}
@Override
public String toString() {
return "Student [name=" + name + ", id=" + id + ", email=" + email
+ ", sdate=" + sdate + "]
";
}
}
3.MybatisUtil 工具类
package com.rindy.maven.utils;
import java.io.IOException;
import java.io.InputStream;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class MybatisUtil {
private static Logger log=LoggerFactory.getLogger(MybatisUtil.class);
private static SqlSessionFactory factory;
static{
try {
log.debug("载入mybatis.xml的配置文件");
InputStream in =Resources.getResourceAsStream("mybatis.xml");
log.debug("载入mybatis.xml的配置文件成功");
log.debug("通过配置文件的数据构建sql session工厂");
factory=new SqlSessionFactoryBuilder().build(in);
log.debug("通过配置文件的数据构建sql session工厂 【成功】" );
log.debug("生产sqlsession 工厂对象");
} catch (IOException e) {
e.printStackTrace();
log.debug("载入mybatis.xml的配置文件失败",e);
}
}
public static SqlSession getSession(){
//原来这么些
//InputStream in=MybatisUtil.class.getClassLoader().getResourceAsStream("mybatis.xml");
//mybatis这么写
SqlSession session=null;
session=factory.openSession();
log.debug("生产sqlsession 工厂对象 成功");
return session;
}
/**
*
* @param isAutoCommit :true: 自己主动提交事务， false 手动事务
* @return
*/
public static SqlSession getSession(boolean isAutoCommit){
SqlSession session=null;
session=factory.openSession( isAutoCommit );
log.debug("生产sqlsession 工厂对象 成功");
return session;
}
}
sql语句注意常常复习。