Mybatis实例 简单查询 事务处理 关联、集合查询 鉴别器 动态SQL及各种标签实例

Mybatis 实例

testselectSub

Mybatis 工作流程

Mybatis 工作流程
1.读取配置文件
2.生成SqlSessionFactory
3.建立SqlSession
4.调用Mybatis提供的ApI
5.查询MAP配置
6.返回结果

版本信息

Mybatis 3.4.1
JDK 1.8
Eclipse版本 Neon.1a Release (4.6.1)
数据库 MySQL5.7

源代码

数据库

db_mybatis

mysql> show tables;
+----------------------+
| Tables_in_db_mybatis |
+----------------------+
| tb_author            |
| tb_reader            |
| tb_user              |
| tb_visit             |
+----------------------+

mysql> desc tb_author;
+----------+-------------+------+-----+---------+----------------+
| Field    | Type        | Null | Key | Default | Extra          |
+----------+-------------+------+-----+---------+----------------+
| id       | int(11)     | NO   | PRI | NULL    | auto_increment |
| realName | varchar(20) | YES  |     | NULL    |                |
| userID   | int(11)     | YES  |     | NULL    |                |
| IDCard   | varchar(20) | YES  |     | NULL    |                |
+----------+-------------+------+-----+---------+----------------+
+----+----------+--------+-----------------+
| id | realName | userID | IDCard          |
+----+----------+--------+-----------------+
|  1 | 金庸     |      5 | 360060040604064 |
|  2 | 古龙     |      7 | 360060040604067 |
+----+----------+--------+-----------------+

mysql> desc tb_user;
+----------+--------------+------+-----+---------+----------------+
| Field    | Type         | Null | Key | Default | Extra          |
+----------+--------------+------+-----+---------+----------------+
| id       | int(11)      | NO   | PRI | NULL    | auto_increment |
| username | varchar(255) | YES  |     | NULL    |                |
| password | varchar(255) | YES  |     | NULL    |                |
+----------+--------------+------+-----+---------+----------------+
+----+----------+----------+
| id | username | password |
+----+----------+----------+
|  2 | 慕容复   | 666666   |
|  4 | 段誉     | 122435   |
|  5 | 虚竹     | 43534    |
|  7 | 木婉清   | 998989   |
+----+----------+----------+

mysql> desc tb_reader;
+----------+---------+------+-----+---------+----------------+
| Field    | Type    | Null | Key | Default | Extra          |
+----------+---------+------+-----+---------+----------------+
| readerID | int(11) | NO   | PRI | NULL    | auto_increment |
| userID   | int(11) | YES  |     | NULL    |                |
| money    | int(11) | YES  |     | NULL    |                |
+----------+---------+------+-----+---------+----------------+
+----------+--------+-------+
| readerID | userID | money |
+----------+--------+-------+
|        1 |      2 |   100 |
|        2 |      4 |   300 |
|        3 |      5 |   700 |
|        4 |      7 |   200 |
+----------+--------+-------+

mysql> desc tb_visit;
+-----------+--------------+------+-----+---------+----------------+
| Field     | Type         | Null | Key | Default | Extra          |
+-----------+--------------+------+-----+---------+----------------+
| visitID   | int(11)      | NO   | PRI | NULL    | auto_increment |
| userID    | int(11)      | YES  |     | NULL    |                |
| visitDate | date         | YES  |     | NULL    |                |
| visitIP   | varchar(100) | YES  |     | NULL    |                |
+-----------+--------------+------+-----+---------+----------------+
+---------+--------+------------+-------------+
| visitID | userID | visitDate  | visitIP     |
+---------+--------+------------+-------------+
|       1 |      2 | 2016-11-12 | 12312.12312 |
+---------+--------+------------+-------------+

mysql> create table tb_reader (
-> readerID int primary key auto_increment,
-> userID int,
-> money int);
Query OK, 0 rows affected (0.51 sec)

tb_user表的主键 id 对应其他表的外键userID列

log4j.properties

配置文件

log4j.properties

log4j.rootLogger=DEBUG,Console
log4j.appender.Console=org.apache.log4j.ConsoleAppender
log4j.appender.Console.layout=org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern=%d [%t] %-5p [%c] - %m%n

log4j.logger.org.apache=INFO
log4j.logger.java.sql.ResultSet=INFO
log4j.logger.java.sql.PreparedStatement=DEBUG
log4j.logger.java.sql.Statement=DEBUG
log4j.logger.java.sql.Connection=DEBUG

com.jxust.config

包

Configuration.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>
<settings>
<!--  懒加载 -->
<setting name="lazyLoadingEnabled" value="true"/>
<setting name="aggressiveLazyLoading" value="false"/>
</settings>
<!-- 定义别名在 User.xml中引用，可以不用写冗长的包名 -->
<typeAliases>
<typeAlias alias="User" type="com.jxust.pojo.User"/>
<typeAlias alias="Author" type="com.jxust.pojo.Author"/>
</typeAliases>

<!-- 连接数据库配置 -->
<environments default="development">
<environment id="development">
<transactionManager type="JDBC">

</transactionManager>

<dataSource type="UNPOOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://127.0.0.1:3306/db_mybatis?characterEncoding=utf8&useSSL=false"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
</dataSource>
</environment>
</environments>

<mappers>
<mapper resource="com/jxust/config/sqlxml/User.xml"/>
<mapper resource="com/jxust/config/sqlxml/Author.xml"/>
<mapper resource="com/jxust/config/sqlxml/MyReader.xml"/>
<!-- 应用接口来实现删除方法 -->
<mapper class="com.jxust.config.sqlxml.InterfaceUserMap"/>
</mappers>

</configuration>

com.jxust.pojo

包

User.java

package com.jxust.pojo;

import java.util.List;

/**
* 用户信息类对应数据库 tb_user表
* User（用户）包含 Author（作者）和 Reader（读者）
* @author Peng
* @Date2016年11月20日下午2:55:02
*/
public class User {
private int id;
private String username;
private String password;
private List<Visit> visitList;
// visitList 记入登录事件，每次登录就记入一条数据，所以用List集合

public User() {
super();
}

public User(String username, String password) {
super();
this.username = username;
this.password = password;
}
//setter and getter

@Override
public String toString() {
return "User [id=" + id + ", username=" + username + ", password=" + password + "]";
}
}

Author.java

package com.jxust.pojo;
/**
* 作者信息类 对应数据表tb_author
* 包含User组件类型
* User a_user对应列userID(外键）
* @author Peng
* @Date2016年11月20日下午2:55:18
*/
public class Author {
private Integer id;//自增主键
private User a_user;//外键引用tb_user表
private String realName;//真实姓名
private String IDCard;//身份证

//setter and getter
}

Visit.java

package com.jxust.pojo;

import java.util.Date;
/**
* 记录User用户登录的时间，IP信息
* 对应表 tb_visit 表中的 userID键对应v_user
* @author Peng
* @Date2016年11月21日下午5:06:15
*/
public class Visit {
private Integer visitID;
private User v_user;
private Date visitDate;
private String visitIP;

//setter and getter
@Override
public String toString() {
return "Visit [visitID=" + visitID + ", visitDate=" + visitDate + ", visitIP=" + visitIP + "]";
}
}

MyReader.java

package com.jxust.pojo;
/**
* 记录读者的money，对应表 tb_reader
* @author Peng
* @Date2016年11月21日上午11:07:33
*/
public class MyReader {

private Integer readerID;
private User r_user;//外键userID，对应tb_user表的主键id
private Integer money;

//setter and getter
@Override
public String toString() {
return "MyReader [readerID=" + readerID + ", money=" + money + "]";
}
}

com.jxust.config.sql.xml

包

User.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="/">

<!-- 配置数据库字段和Message字段 -->
<resultMap type="com.jxust.pojo.User" id="UserResult">
<!-- id 主键，result其他列名 -->
<!--column属性表示从数据库中查询的属性，property则表示查询出来的属性对应的值赋给实体对象的哪个属性 -->
<id column="id" jdbcType="INTEGER" property="id" />
<result column="username" jdbcType="VARCHAR" property="username" />
<result column="password" jdbcType="VARCHAR" property="password" />
</resultMap>

<!-- 和visit表做集合查询 -->
<resultMap type="User" id="visitMap">
<id property="id" column="id" />
<result property="username" column="username" />
<result column="password" property="password" />
<collection property="visitList" javaType="ArrayList"
column="userID" ofType="com.jxust.pojo.Visit">
<result property="visitID" column="visitID" />
<result property="visitDate" column="visitDate" />
<result property="visitIP" column="visitIP" />
</collection>

</resultMap>

<!-- 根据id查询 -->
<select id="findById" parameterType="int" resultType="com.jxust.pojo.User">
SELECT * FROM tb_user WHERE id=#{id}
</select>

<!--插入数据 User使用了别名，在配置文件中声明了 -->
<insert id="insertUser" parameterType="User" statementType="PREPARED"
keyProperty="id" useGeneratedKeys="true">
INSERT INTO tb_user (username,password) VALUES
(#{username},#{password})
</insert>

<!-- 更新数据 -->
<update id="updateuser" parameterType="User">
UPDATE tb_user SET
username =#{username,jdbcType=VARCHAR},
password=#{password,jdbcType=VARCHAR}
WHERE id=#{id,jdbcType=VARCHAR}
</update>
<!-- ****************************************************** -->
<!-- 删除数据 -->
<delete id="deleteuser" parameterType="int">
DELETE FROM tb_user WHERE
id=#{id}
</delete>

<!-- HashMap查询 -->
<select id="hashmapselect" resultType="User" parameterType="hashmap">
SELECT * FROM tb_user WHERE username=#{username} AND
password=#{password}
</select>

<!-- 对象查询 返回类型和参数类型都是User -->
<select id="objectselect" resultType="User" parameterType="User">
SELECT * FROM tb_user WHERE username=#{username} AND
password=#{password}
</select>

<!-- 返回多行数据 -->
<select id="selectUserList" resultType="User">
SELECT * FROM tb_user
</select>

<!-- resultType 和 resultMap两者只能使用其中一个 -->
<select id="selectUsers" resultMap="UserResult">
SELECT id,username,password
FROM tb_user
</select>
<!-- 集合查询 -->
<select id="selectVisit" resultMap="visitMap">
SELECT * FROM tb_user INNER
JOIN tb_visit ON tb_user.id = tb_visit.userID
</select>

<!-- 测试 chooose 动态sql 用了别名 -->
<select id="selectUserChoose" resultType="User" parameterType="User">
SELECT * FROM tb_user WHERE 1=1
<choose>
<when test="username!=null">
AND username like #{username}
</when>
<when test="id!=0">
AND id=#{id}
</when>
<otherwise>
AND password IS NOT NULL
</otherwise>
</choose>
</select>

<!-- 测试 where 动态sql -->
<select id="selectUserWhere" resultType="User" parameterType="User">
SELECT * FROM tb_user
<where>
<if test="username!=null">
AND username like #{username}
</if>
<if test="id!=0">
AND id =#{id}
</if>
</where>
</select>

<!-- 测试 <set> 动态sql -->
<!--相对于 UPDATE tb_user SET username= '虚竹' WHERE id =5; 的SET 会判断,的添加 -->
<update id="updateUserSet" parameterType="User">
UPDATE tb_user
<set>
<if test="username!=null">
username = #{username},
</if>
<if test="password!=null">
password = #{password},
</if>
</set>
WHERE id=#{id}
</update>

<!-- 测试<trim>标签 -->
<!-- prefix 前缀增加 suffix 后缀增加 prefixOverrides 自动判断前置 suffixOverrides 自动判断后置 -->
<select id="selectUserTrim" parameterType="User" resultType="User">
SELECT * FROM tb_user
<trim prefix="WHERE" prefixOverrides="AND|OR">
<if test="username!=null and username!='' ">
AND username like #{username}
</if>
<if test="password!=null and password!='' ">
AND password =#{password}
</if>
</trim>
</select>
<!-- 测试<trim>标签 2-->
<!-- 智能添加后缀,如果你username和password都没有赋值，则，语句为  UPDATE tb_user当然，这个语句会报错 -->
<update id="updateUserTrim" parameterType="USer">
UPDATE tb_user
<trim prefix="SET" suffixOverrides="," suffix="WHERE id=#{id}">
<if test="username != null and username != '' ">
username = #{username},
</if>
<if test="password != null and password != '' ">
password = #{password},
</if>
</trim>
</update>

<!-- 测试foreach标记 -->
<!-- 这里可以不指定 parameterType  -->
<select id="selectUserforeach" parameterType="java.util.List" resultType="User">
SELECT * FROM tb_user
<where>
id IN
<foreach item="item" index="index" collection="list"
open="(" separator=","  close=")">
#{item}
</foreach>
</where>
</select>
</mapper>

Author.java

<?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="/">

<!--**联合查询 resultMap** -->
<!-- 配置数据库字段和Message字段  没有使用别名，怕混淆-->
<resultMap type="com.jxust.pojo.Author" id="AuthorresultMapByJoin">
<!--  column属性表示从数据库中查询的属性，property则表示查询出来的属性对应的值赋给实体对象的哪个属性 -->
<id column="tb_author.id" jdbcType="INTEGER" property="id"/>
<result column="realName" jdbcType="VARCHAR" property="realName"/>
<result column="IDCard" jdbcType="VARCHAR" property="IDCard"/>
<!-- property为Author类中private User a_user;column为数据库表中的列userID -->
<!-- 两个表的id相同，为了区分，使用表名加id，tb_user.id 和 tb_author.id -->
<association property="a_user" column="userID" javaType="com.jxust.pojo.User">
<id column="tb_user.id" jdbcType="INTEGER" property="id"/>
<result column="username" jdbcType="VARCHAR" property="username"/>
<result column="password" jdbcType="VARCHAR" property="password"/>
</association>
</resultMap>

<!-- **构造查询方式resultMap** -->
<resultMap type="com.jxust.pojo.Author" id="AuthorresultMapByCon">
<id column="tb_author.id" jdbcType="INTEGER" property="id"/>
<result column="realName" jdbcType="VARCHAR" property="realName"/>
<result column="IDCard" jdbcType="VARCHAR" property="IDCard"/>
<association property="a_user" column="userID" javaType="com.jxust.pojo.User">
<constructor>
<arg column="username" javaType="String" />
<arg column="password" javaType="String"/>
</constructor>
</association>
</resultMap>

<!-- **子查询方式resultMap** -->
<resultMap type="com.jxust.pojo.Author" id="AuthorresultMapBySub">
<id column="tb_author.id" jdbcType="INTEGER" property="id"/>
<result column="realName" jdbcType="VARCHAR" property="realName"/>
<result column="IDCard" jdbcType="VARCHAR" property="IDCard"/>
<association property="a_user" column="userID" javaType="com.jxust.pojo.User"
select="findById">
<!-- 会把userId 传入到findById（在User.xml文件中)查询中 -->
</association>
</resultMap>

<!-- *********************************************************** -->
<!-- 插入一条数据 -->
<insert id="insertAuthor" parameterType="Author" >
INSERT INTO tb_author (userID,realName,IDCard)
VALUES(#{a_user.id},#{realName},#{IDCard})
</insert>

<!--联合查询  -->
<select id="selectAuthorJoin" resultMap="AuthorresultMapByJoin">
SELECT * FROM tb_author INNER JOIN tb_user
ON tb_user.id = tb_author.userID
</select>
<!-- 联合查询 注意引用的resultMap不同 -->
<select id="selectAuthorCon" resultMap="AuthorresultMapByCon">
SELECT * FROM tb_author INNER JOIN tb_user
ON tb_user.id = tb_author.userID
</select>

<!-- 子查询 -->
<select id="selectAuthorSub" resultMap="AuthorresultMapBySub">
SELECT * FROM tb_author
</select>
</mapper>

InterfaceUserMap.java

package com.jxust.config.sqlxml;

import org.apache.ibatis.annotations.Delete;

public interface InterfaceUserMap {

@Delete("DELETE FROM tb_user WHERE id=#{id}")
public void deleteoneuser(Integer id);
}

MyReader.java

<?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="/">

<!-- 测试 if 动态sql -->
<select id="selectReaderMoney" resultType="com.jxust.pojo.MyReader"
parameterType="com.jxust.pojo.MyReader">
SELECT * FROM tb_reader
WHERE 1=1
<if test="money!=null">
and money>#{money}
</if>
</select>

</mapper>

com.jxust.test

MybatisTest.java

package com.jxust.test;

import org.junit.Test;

import com.jxust.config.sqlxml.InterfaceUserMap;
import com.jxust.pojo.User;

import java.io.IOException;
import java.io.Reader;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
/**
* 简单的增删改查
* @author Peng
* @Date2016年11月20日上午11:27:07
*/
public class MybatisTest {
/**
* 测试查询
* @throws IOException
*/
@Test
public void testfindById() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
//通过配置信息构建一个SqlSessionFactory
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
//通过SqlSessionFactory打开一个数据库会话
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
User user = sqlSession.selectOne("findById", 2);
System.out.println(user.toString());
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}

}
/**
* 测试插入一条数据
* @throws IOException
*/
@Test
public void testinsert() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
User user = new User();
user.setUsername("段誉");
user.setPassword("122435");
sqlSession.insert("insertUser",user);
sqlSession.commit();
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}
/**
* 更新数据
* @throws IOException
*/
@Test
public void testupdate() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
User user = new User();
user.setUsername("慕容复");
user.setPassword("666666");
user.setId(2);
sqlSession.update("updateuser", user);
sqlSession.commit();
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}

/**
* 删除数据，利用注解的方式（使用接口) 不推荐
* @throws IOException
*/
@Test
public void testdelete() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
InterfaceUserMap ium = sqlSession.getMapper(InterfaceUserMap.class);
ium.deleteoneuser(1);
sqlSession.commit();
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}

/**
* 删除数据，采用xml文件
* @throws IOException
*/
@Test
public void testdelete2() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
sqlSession.delete("deleteuser", 3);
sqlSession.commit();
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}
}

MybatisTest2.java

package com.jxust.test;

import java.io.IOException;
import java.io.Reader;
import java.util.HashMap;
import java.util.List;

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.junit.Test;

import com.jxust.pojo.User;
/**
* 简单查询、多行查询
* @author Peng
* @Date2016年11月20日上午11:28:31
*/
public class MybatisTest2 {
/**
* 测试hashmap查询
* @throws IOException
*/
@Test
public void testlogin() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
//通过配置信息构建一个SqlSessionFactory
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
//通过SqlSessionFactory打开一个数据库会话
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
HashMap<String,String> map = new HashMap<>();
map.put("username", "慕容复");
map.put("password", "666666");
User user =sqlSession.selectOne("hashmapselect",map);
if(user!=null){
System.out.println("登录成功！");
}
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}
/**
* 测试对象查询
* @throws IOException
*/
@Test
public void testlogin2() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
//通过配置信息构建一个SqlSessionFactory
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
//通过SqlSessionFactory打开一个数据库会话
SqlSession sqlSession = sqlSessionFactory.openSession();
try {

User user = new User();
user.setUsername("慕容复");
user.setPassword("666666");
User rs_user =sqlSession.selectOne("objectselect",user);
if(rs_user!=null){
System.out.println("登录成功！");
}
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}

/**
* 测试多行查询
* @throws IOException
*/
@Test
public void testselectlist() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
//通过配置信息构建一个SqlSessionFactory
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
//通过SqlSessionFactory打开一个数据库会话
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
List<User> list = sqlSession.selectList("selectUserList");
for(User s :list){
System.out.println(s.toString());
}
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}

/**
* 测试resultMap查询
* @throws IOException
*/
@Test
public void testselectresultMap() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
//通过配置信息构建一个SqlSessionFactory
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
//通过SqlSessionFactory打开一个数据库会话
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
List<User> list = sqlSession.selectList("selectUsers");
for(User s :list){
System.out.println(s.toString());
}
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}
}

MybatisTest3.java

package com.jxust.test;

import java.io.IOException;
import java.io.Reader;

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.junit.Test;

import com.jxust.pojo.Author;
import com.jxust.pojo.User;
/**
* 测试事务
* @author Peng
* @Date2016年11月20日下午2:38:02
*/
public class MybatisTest3 {
/**
* 测试添加数据，人为制造错误，查看事务回滚效果
* @throws IOException
*/
@Test
public void testinsertTranscation() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession(false);
//默认为false
try {
User one = new User();
one.setUsername("author02");
one.setPassword("43535");
//存入数据库之后，id值自动生成
sqlSession.insert("insertUser",one);
System.out.println("新加入的user id为"+one.getId());

Author au = new Author();
au.setUser(one);
au.setRealName("古龙");
au.setIDCard("360060040604067");

sqlSession.insert("insertAuthor",au);
sqlSession.commit();
} catch (Exception e) {
e.printStackTrace();
//事务回滚
sqlSession.rollback();
}finally {
sqlSession.close();
}
}
}

MybatisTest4.java

package com.jxust.test;

import java.io.IOException;
import java.io.Reader;
import java.util.List;

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.junit.Test;

import com.jxust.pojo.Author;
/**
* 测试关联查询
* @author Peng
* @Date2016年11月20日下午3:37:10
*/
public class MybatisTest4 {
/**
* 测试关联查询-联合查询
* @throws IOException
*/
@Test
public void testselectJoin() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
List<Author> list = sqlSession.selectList("selectAuthorJoin");
for(Author a:list){
System.out.println("作者姓名："+a.getRealName()+","+
"对应用户名："+a.getUser().getUsername());
}
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}

/**
* 测试关联查询-构造查询
* @throws IOException
*/
@Test
public void testselectConstruct() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
List<Author> list = sqlSession.selectList("selectAuthorCon");
for(Author a:list){
System.out.println("作者姓名："+a.getRealName()+","+
"对应用户名："+a.getUser().getUsername());
}
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}

/**
* 测试关联查询-子查询
* @throws IOException
*/
@Test
public void testselectSub() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
List<Author> list = sqlSession.selectList("selectAuthorSub");
for(Author a:list){

//System.out.println("作者姓名："+a.getRealName()+","+
//"对应用户名："+a.getUser().getUsername());
System.out.println("作者姓名："+a.getRealName());
System.out.println("懒加载应用.....");

/* -----------------这里有错误--------------*/
//设置为懒加载后会出现空指针异常，没有执行findById查询
if(a.getUser()==null){
System.out.println("a.getUser()为空");
}
System.out.println("对应用户名："+a.getUser().getUsername());
}
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}
}

MybatisTest5.java

package com.jxust.test;

import java.io.IOException;
import java.io.Reader;
import java.util.List;

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.junit.Test;

import com.jxust.pojo.User;
import com.jxust.pojo.Visit;
/**
* 测试集合查询
* @author Peng
* @Date2016年11月20日下午8:05:19
*/
public class MybatisTest5 {
/**
* 测试集合查询
* 集合查询特定用于当你查询的对象中含有另一个对象的集合引用时
* @throws IOException
*/
@Test
public void testselectColl() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
List<User> list = sqlSession.selectList("selectVisit");
for(User u:list){
System.out.println(u.toString());
for(Visit v:u.getVisitList()){
System.out.println(v.toString());
}
}
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}
}

MybatisTest6.java

package com.jxust.test;

import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;

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.junit.Test;

import com.jxust.pojo.MyReader;
import com.jxust.pojo.User;
/**
* 测试动态SQL
* @author Peng
* @Date2016年11月20日下午8:05:19
*/
public class MybatisTest6 {
/**
* 测试 <if>标记
* 在Myreader.xml文件中配置的
* @throws IOException
*/
@Test
public void testselectIF() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
MyReader myreader = new MyReader();
//myreader.setMoney(200);
List<MyReader> list = sqlSession.selectList("selectReaderMoney",myreader);
for(MyReader m:list){
System.out.println(m.toString());
}
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}

/**
* 测试 <choose>标记
* 非常像switch
*  在User.xml文件中配置的
* @throws IOException
*/
@Test
public void testselectChoose() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
User user = new User();
//user.setUsername("%段%");
//user.setId(4);
//可以设置
List<User> list = sqlSession.selectList("selectUserChoose",user);
for(User s:list){
System.out.println(s.toString());
}
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}

/**
* 测试 <where>标记
*  在User.xml文件中配置的
*  就是<where>替换掉sql语句中的WHERE，就不用写1=1了，
*  <where>智能的判断该不该加WHERE
*  避免  SELECT * FROM tb_user WHERE ，WHERE后面没内容，出现语法错误
* @throws IOException
*/
@Test
public void testselectWhere() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
User user = new User();
//user.setUsername("%段%");
user.setId(4);
List<User> list = sqlSession.selectList("selectUserWhere",user);
for(User s:list){
System.out.println(s.toString());
}
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}

/**
* 测试 <set>标记
*  在User.xml文件中配置的
* 智能判断set 内容后面的","
*  UPDATE tb_user SET username= '虚竹',..., WHERE ...
* @throws IOException
*/
@Test
public void testupdateSet() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
User user = new User();
user.setUsername("木婉清");
//user.setPassword("998989");
user.setId(7);
sqlSession.update("updateUserSet",user);
sqlSession.commit();//注意要提交
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}

/**
* 测试 <trim>标记
*  在User.xml文件中配置的
*
* @throws IOException
*/
@Test
public void testselectTrim() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
User user = new User();
user.setUsername("%段%");
//user.setPassword("122435");
List<User> list = sqlSession.selectList("selectUserTrim",user);
for(User s:list){
System.out.println(s.toString());
}
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}

/**
* 测试 <trim标记
*  在User.xml文件中配置的
*
* @throws IOException
*/
@Test
public void testupdateTrim() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
User user = new User();
//user.setUsername("木婉清");
//user.setPassword("998989");
user.setId(7);
sqlSession.update("updateUserTrim",user);
sqlSession.commit();//注意要提交
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}
/**
* 测试<foreach>标记
* @throws IOException
*/
@Test
public void testselectForeach() throws IOException{
Reader reader =Resources.getResourceAsReader("com/jxust/config/Configuration.xml");
SqlSessionFactory sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
List<Integer> list = new ArrayList<>();
list.add(1);
list.add(2);
list.add(5);
List<User> userlist = sqlSession.selectList("selectUserforeach",list);
for(User s:userlist){
System.out.println(s.toString());
}
} catch (Exception e) {
e.printStackTrace();
}finally {
sqlSession.close();
}
}
}

Mybatis笔记

MyBatis笔记.txt

----------------------------------------------------
mybatisConfig.xml中引用map文件
1
<mapers>
<mapper resource="jxust/map/User.xml"/>
</mappers>
2绝对路径引用
<mapper url ="file:///var/sqlmaps/User.xml/>
3包路径引用
<package name="com.xx.mapperinterface"/>

----------------------------------------------------
mysql> desc tb_user;
+----------+--------------+------+-----+---------+----------------+
| Field    | Type         | Null | Key | Default | Extra          |
+----------+--------------+------+-----+---------+----------------+
| id       | int(11)      | NO   | PRI | NULL    | auto_increment |
| username | varchar(255) | YES  |     | NULL    |                |
| password | varchar(255) | YES  |     | NULL    |                |
+----------+--------------+------+-----+---------+----------------+
3 rows in set (0.00 sec)
----------------------------------------------------
查询数据
2016-11-19 21:33:24,265 [main] DEBUG [User.findById] - ==>  Preparing: select * from tb_user where id=?
2016-11-19 21:33:24,301 [main] DEBUG [User.findById] - ==> Parameters: 1(Integer)
2016-11-19 21:33:24,336 [main] DEBUG [User.findById] - <==      Total: 1
User [id=1, username=李琦, password=123345]
----------------------------------------------------
插入数据
2016-11-19 22:02:54,866 [main] DEBUG [/.insertUser] - ==>  Preparing: insert into tb_user (username,password) values (?,?)
2016-11-19 22:02:54,924 [main] DEBUG [/.insertUser] - ==> Parameters: 慕容复(String), 123445(String)
2016-11-19 22:02:54,961 [main] DEBUG [/.insertUser] - <==    Updates: 1
----------------------------------------------------
插入数据，没有指定的属性为null
2016-11-20 10:21:50,799 [main] DEBUG [/.updateuser] - ==>  Preparing: UPDATE tb_user SET username =?, password=? WHERE id=?
2016-11-20 10:21:50,836 [main] DEBUG [/.updateuser] - ==> Parameters: null, 666666(String), 2(Integer)
2016-11-20 10:21:50,841 [main] DEBUG [/.updateuser] - <==    Updates: 1

username没有赋值
mysql> select * from tb_user;
+----+----------+----------+
| id | username | password |
+----+----------+----------+
|  1 | 李琦     | 123345   |
|  2 | NULL     | 666666   |
+----+----------+----------+
2 rows in set (0.00 sec)

2016-11-20 10:24:02,379 [main] DEBUG [/.updateuser] - ==>  Preparing: UPDATE tb_user SET username =?, password=? WHERE id=?
2016-11-20 10:24:02,413 [main] DEBUG [/.updateuser] - ==> Parameters: 慕容复(String), 666666(String), 2(Integer)
2016-11-20 10:24:02,417 [main] DEBUG [/.updateuser] - <==    Updates: 1

mysql> select * from tb_user;
+----+----------+----------+
| id | username | password |
+----+----------+----------+
|  1 | 李琦     | 123345   |
|  2 | 慕容复   | 666666   |
+----+----------+----------+
2 rows in set (0.00 sec)
----------------------------------------------------
删除一条数据，通过注解的方式，接口的方式
2016-11-20 10:32:02,230 [main] DEBUG [com.jxust.config.sqlxml.InterfaceUserMap.deleteuser] - ==>  Preparing: DELETE FROM tb_user WHERE id=?
2016-11-20 10:32:02,263 [main] DEBUG [com.jxust.config.sqlxml.InterfaceUserMap.deleteuser] - ==> Parameters: 1(Integer)
2016-11-20 10:32:02,267 [main] DEBUG [com.jxust.config.sqlxml.InterfaceUserMap.deleteuser] - <==    Updates: 1

mysql> select * from tb_user;
+----+----------+----------+
| id | username | password |
+----+----------+----------+
|  2 | 慕容复   | 666666   |
+----+----------+----------+
1 row in set (0.00 sec)

----------------------------------------------------
利用hashmap封装数据查询
2016-11-20 11:34:17,236 [main] DEBUG [/.hashmapselect] - ==>  Preparing: SELECT * FROM tb_user WHERE username=? AND password=?
2016-11-20 11:34:17,273 [main] DEBUG [/.hashmapselect] - ==> Parameters: 慕容复(String), 666666(String)
2016-11-20 11:34:17,300 [main] DEBUG [/.hashmapselect] - <==      Total: 1
登录成功！

利用 对象查询
2016-11-20 12:21:25,075 [main] DEBUG [/.objectselect] - ==>  Preparing: SELECT * FROM tb_user WHERE username=? AND password=?
2016-11-20 12:21:25,103 [main] DEBUG [/.objectselect] - ==> Parameters: 慕容复(String), 666666(String)
2016-11-20 12:21:25,115 [main] DEBUG [/.objectselect] - <==      Total: 1
登录成功！
----------------------------------------------------
多行查询
2016-11-20 11:57:39,277 [main] DEBUG [/.selectUserList] - ==>  Preparing: SELECT * FROM tb_user
2016-11-20 11:57:39,303 [main] DEBUG [/.selectUserList] - ==> Parameters:
2016-11-20 11:57:39,317 [main] DEBUG [/.selectUserList] - <==      Total: 2
User [id=2, username=慕容复, password=666666]
User [id=4, username=段誉, password=122435]
----------------------------------------------------
resultMap 方式查询所有
2016-11-20 12:20:15,150 [main] DEBUG [/.selectUsers] - ==>  Preparing: SELECT id,username,password FROM tb_user
2016-11-20 12:20:15,180 [main] DEBUG [/.selectUsers] - ==> Parameters:
2016-11-20 12:20:15,193 [main] DEBUG [/.selectUsers] - <==      Total: 2
User [id=2, username=慕容复, password=666666]
User [id=4, username=段誉, password=122435]
----------------------------------------------------
创建表 Author
mysql> create table Author(
-> id int primary key auto_increment,
-> realName varchar(20),
-> userID int,
-> IDCard varchar(20));
Query OK, 0 rows affected (0.26 sec)

mysql> desc Author;
+----------+-------------+------+-----+---------+----------------+
| Field    | Type        | Null | Key | Default | Extra          |
+----------+-------------+------+-----+---------+----------------+
| id       | int(11)     | NO   | PRI | NULL    | auto_increment |
| realName | varchar(20) | YES  |     | NULL    |                |
| userID   | int(11)     | YES  |     | NULL    |                |
| IDCard   | varchar(20) | YES  |     | NULL    |                |
+----------+-------------+------+-----+---------+----------------+
----------------------------------------------------
执行过程中，其中一个操作出错，则执行回滚
2016-11-20 14:50:04,521 [main] DEBUG [/.insertUser] - ==>  Preparing: INSERT INTO tb_user (username,password) VALUES (?,?)
2016-11-20 14:50:04,548 [main] DEBUG [/.insertUser] - ==> Parameters: author01(String), 43534(String)
2016-11-20 14:50:04,601 [main] DEBUG [/.insertUser] - <==    Updates: 1
新加入的user id为6
org.apache.ibatis.exceptions.PersistenceException:

执行成功，打印出两条sql语句
2016-11-20 14:59:26,725 [main] DEBUG [/.insertUser] - ==>  Preparing: INSERT INTO tb_user (username,password) VALUES (?,?)
2016-11-20 14:59:26,749 [main] DEBUG [/.insertUser] - ==> Parameters: author02(String), 43535(String)
2016-11-20 14:59:26,802 [main] DEBUG [/.insertUser] - <==    Updates: 1
新加入的user id为7
2016-11-20 14:59:26,803 [main] DEBUG [/.insertAuthor] - ==>  Preparing: INSERT INTO tb_author (userID,realName,IDCard) VALUES(?,?,?)
2016-11-20 14:59:26,803 [main] DEBUG [/.insertAuthor] - ==> Parameters: 7(Integer), 古龙(String), 360060040604067(String)
2016-11-20 14:59:26,806 [main] DEBUG [/.insertAuthor] - <==    Updates: 1
----------------------------------------------------
联合查询
2016-11-20 15:46:28,123 [main] DEBUG [/.selectAuthorJoin] - ==>  Preparing: SELECT * FROM tb_author INNER JOIN tb_user ON tb_user.id = tb_author.userID
2016-11-20 15:46:28,152 [main] DEBUG [/.selectAuthorJoin] - ==> Parameters:
2016-11-20 15:46:28,168 [main] DEBUG [/.selectAuthorJoin] - <==      Total: 2
作者姓名：金庸,对应用户名：author01
作者姓名：古龙,对应用户名：author02
----------------------------------------------------
构造查询
2016-11-20 17:02:05,165 [main] DEBUG [/.selectAuthorCon] - ==>  Preparing: SELECT * FROM tb_author INNER JOIN tb_user ON tb_user.id = tb_author.userID
2016-11-20 17:02:05,194 [main] DEBUG [/.selectAuthorCon] - ==> Parameters:
2016-11-20 17:02:05,211 [main] DEBUG [/.selectAuthorCon] - <==      Total: 2
作者姓名：金庸,对应用户名：author01
作者姓名：古龙,对应用户名：author02
----------------------------------------------------
子查询
2016-11-20 16:59:59,687 [main] DEBUG [/.selectAuthorSub] - ==>  Preparing: SELECT * FROM tb_author
2016-11-20 16:59:59,714 [main] DEBUG [/.selectAuthorSub] - ==> Parameters:
2016-11-20 16:59:59,732 [main] DEBUG [/.findById] - ====>  Preparing: SELECT * FROM tb_user WHERE id=?
2016-11-20 16:59:59,733 [main] DEBUG [/.findById] - ====> Parameters: 5(Integer)
2016-11-20 16:59:59,735 [main] DEBUG [/.findById] - <====      Total: 1
2016-11-20 16:59:59,736 [main] DEBUG [/.findById] - ====>  Preparing: SELECT * FROM tb_user WHERE id=?
2016-11-20 16:59:59,736 [main] DEBUG [/.findById] - ====> Parameters: 7(Integer)
2016-11-20 16:59:59,738 [main] DEBUG [/.findById] - <====      Total: 1
2016-11-20 16:59:59,738 [main] DEBUG [/.selectAuthorSub] - <==      Total: 2
作者姓名：金庸,对应用户名：author01
作者姓名：古龙,对应用户名：author02
----------------------------------------------------
mysql> use db_mybatis;
Database changed
mysql> create table visit(
-> visitID int primary key auto_increment,
-> userID int ,
-> visitDate Date,
-> visitIP varchar(100));
Query OK, 0 rows affected (0.24 sec)
mysql> desc visit;
+-----------+--------------+------+-----+---------+----------------+
| Field     | Type         | Null | Key | Default | Extra          |
+-----------+--------------+------+-----+---------+----------------+
| visitID   | int(11)      | NO   | PRI | NULL    | auto_increment |
| userID    | int(11)      | YES  |     | NULL    |                |
| visitDate | date         | YES  |     | NULL    |                |
| visitIP   | varchar(100) | YES  |     | NULL    |                |
+-----------+--------------+------+-----+---------+----------------+
4 rows in set (0.00 sec)

mysql> rename table visit to tb_visit;
Query OK, 0 rows affected (0.23 sec)

mysql> show tables;
+----------------------+
| Tables_in_db_mybatis |
+----------------------+
| tb_author            |
| tb_user              |
| tb_visit             |
+----------------------+
3 rows in set (0.00 sec)
----------------------------------------------------
集合查询，password 为null 是因为我在设置resultMap 时没有加<result column="password" property="password"/>
所以这就是resultMap的特点，结果集映射，自己定义类型，有collection查询 和association查询两种方式，关联查询又分联合，构造，子查询
2016-11-20 20:08:47,473 [main] DEBUG [/.selectVisit] - ==>  Preparing: SELECT * FROM tb_user INNER JOIN tb_visit ON tb_user.id = tb_visit.userID
2016-11-20 20:08:47,500 [main] DEBUG [/.selectVisit] - ==> Parameters:
2016-11-20 20:08:47,518 [main] DEBUG [/.selectVisit] - <==      Total: 1
User [id=2, username=慕容复, password=null]
Visit [visitID=1, visitDate=Sat Nov 12 00:00:00 CST 2016, visitIP=12312.12312]
----------------------------------------------------
mysql> show tables;
+----------------------+
| Tables_in_db_mybatis |
+----------------------+
| tb_author            |
| tb_user              |
| tb_visit             |
+----------------------+
3 rows in set (0.00 sec)
----------------------------------------------------
新建一张表 tb_reader
mysql> create table tb_reader (
-> readerID int primary key auto_increment,
-> userID int,
-> money int);
Query OK, 0 rows affected (0.51 sec)

mysql>
mysql> show tables;
+----------------------+
| Tables_in_db_mybatis |
+----------------------+
| tb_author            |
| tb_reader            |
| tb_user              |
| tb_visit             |
+----------------------+
4 rows in set (0.00 sec)

mysql> desc tb_reader;
+----------+---------+------+-----+---------+----------------+
| Field    | Type    | Null | Key | Default | Extra          |
+----------+---------+------+-----+---------+----------------+
| readerID | int(11) | NO   | PRI | NULL    | auto_increment |
| userID   | int(11) | YES  |     | NULL    |                |
| money    | int(11) | YES  |     | NULL    |                |
+----------+---------+------+-----+---------+----------------+
3 rows in set (0.08 sec)
----------------------------------------------------
测试if拼接查询

设置为money大于200   myreader.setMoney(200);
2016-11-21 11:24:39,709 [main] DEBUG [/.selectReaderMoney] - ==>  Preparing: SELECT * FROM tb_reader WHERE 1=1 and money>?
2016-11-21 11:24:39,733 [main] DEBUG [/.selectReaderMoney] - ==> Parameters: 200(Integer)
2016-11-21 11:24:39,782 [main] DEBUG [/.selectReaderMoney] - <==      Total: 2
MyReader [readerID=2, money=300]
MyReader [readerID=3, money=700]

将设置money注释 //myreader.setMoney(200);则查询所有
2016-11-21 11:26:58,290 [main] DEBUG [/.selectReaderMoney] - ==>  Preparing: SELECT * FROM tb_reader WHERE 1=1
2016-11-21 11:26:58,314 [main] DEBUG [/.selectReaderMoney] - ==> Parameters:
2016-11-21 11:26:58,328 [main] DEBUG [/.selectReaderMoney] - <==      Total: 4
MyReader [readerID=1, money=100]
MyReader [readerID=2, money=300]
MyReader [readerID=3, money=700]
MyReader [readerID=4, money=200]
----------------------------------------------------
测试choose标签
user.setUsername("%段%");
user.setId(4);

2016-11-21 13:53:21,779 [main] DEBUG [/.selectUserChoose] - ==>  Preparing: SELECT * FROM tb_user WHERE 1=1 AND username like ?
2016-11-21 13:53:21,820 [main] DEBUG [/.selectUserChoose] - ==> Parameters: %段%(String)
2016-11-21 13:53:21,848 [main] DEBUG [/.selectUserChoose] - <==      Total: 1
User [id=4, username=段誉, password=122435]

//user.setUsername("%段%");
user.setId(4);

2016-11-21 13:55:20,505 [main] DEBUG [/.selectUserChoose] - ==>  Preparing: SELECT * FROM tb_user WHERE 1=1 AND id=?
2016-11-21 13:55:20,531 [main] DEBUG [/.selectUserChoose] - ==> Parameters: 4(Integer)
2016-11-21 13:55:20,543 [main] DEBUG [/.selectUserChoose] - <==      Total: 1
User [id=4, username=段誉, password=122435]

//user.setUsername("%段%");
///user.setId(4);
都注释后，因为User类中 id的类型为int型，没有设置的时候，默认为0，出现下面的语句，应该把id判断为0，而不是空

2016-11-21 13:55:20,505 [main] DEBUG [/.selectUserChoose] - ==>  Preparing: SELECT * FROM tb_user WHERE 1=1 AND id=?
2016-11-21 13:55:20,531 [main] DEBUG [/.selectUserChoose] - ==> Parameters: 0(Integer)
2016-11-21 13:55:20,543 [main] DEBUG [/.selectUserChoose] - <==      Total: 0

把SELECT中的语句id判断是否为0,出现判断password的值
<when test="id!=0">
AND id=#{id}
</when>

2016-11-21 13:59:33,054 [main] DEBUG [/.selectUserChoose] - ==>  Preparing: SELECT * FROM tb_user WHERE 1=1 AND password IS NOT NULL
2016-11-21 13:59:33,098 [main] DEBUG [/.selectUserChoose] - ==> Parameters:
2016-11-21 13:59:33,110 [main] DEBUG [/.selectUserChoose] - <==      Total: 4
User [id=2, username=慕容复, password=666666]
User [id=4, username=段誉, password=122435]
User [id=5, username=author01, password=43534]
User [id=7, username=author02, password=43535]
--------------------------------------------------
测试<where>标签
username 和 id 都没有添加，查询的是下面的语句
2016-11-21 14:23:18,714 [main] DEBUG [/.selectUserWhere] - ==>  Preparing: SELECT * FROM tb_user
2016-11-21 14:23:18,740 [main] DEBUG [/.selectUserWhere] - ==> Parameters:
2016-11-21 14:23:18,754 [main] DEBUG [/.selectUserWhere] - <==      Total: 4
User [id=2, username=慕容复, password=666666]
User [id=4, username=段誉, password=122435]
User [id=5, username=author01, password=43534]
User [id=7, username=author02, password=43535]
--------------------------------------------------
set 标签测试，逗号被智能去除了
2016-11-21 14:43:44,303 [main] DEBUG [/.updateUserSet] - ==>  Preparing: UPDATE tb_user SET username = ? WHERE id=?
2016-11-21 14:43:44,328 [main] DEBUG [/.updateUserSet] - ==> Parameters: 木婉清(String), 7(Integer)
2016-11-21 14:43:44,380 [main] DEBUG [/.updateUserSet] - <==    Updates: 1

mysql> select* from tb_user;
+----+----------+----------+
| id | username | password |
+----+----------+----------+
|  2 | 慕容复   | 666666   |
|  4 | 段誉     | 122435   |
|  5 | 虚竹     | 43534    |
|  7 | author02 | 43535    |
+----+----------+----------+
4 rows in set (0.00 sec)

mysql> select* from tb_user;
+----+----------+----------+
| id | username | password |
+----+----------+----------+
|  2 | 慕容复   | 666666   |
|  4 | 段誉     | 122435   |
|  5 | 虚竹     | 43534    |
|  7 | 木婉清   | 43535    |
+----+----------+----------+
4 rows in set (0.00 sec)
--------------------------------------------------
<!-- 测试<trim>标签 -->
user.setUsername("%段%");
//user.setPassword("122435");
List<User> list = sqlSession.selectList("selectUserTrim",user);
2016-11-21 15:14:41,513 [main] DEBUG [/.selectUserTrim] - ==>  Preparing: SELECT * FROM tb_user WHERE username like ?
2016-11-21 15:14:41,537 [main] DEBUG [/.selectUserTrim] - ==> Parameters: %段%(String)
2016-11-21 15:14:41,550 [main] DEBUG [/.selectUserTrim] - <==      Total: 1
User [id=4, username=段誉, password=122435]
4 rows in set (0.00 sec)

<!-- 测试<trim>标签2 -->
//user.setUsername("木婉清");
user.setPassword("998989");
user.setId(7);
sqlSession.update("updateUserTrim",user);
sqlSession.commit();//注意要提交
2016-11-21 15:23:00,263 [main] DEBUG [/.updateUserTrim] - ==>  Preparing: UPDATE tb_user SET password = ? WHERE id=?
2016-11-21 15:23:00,288 [main] DEBUG [/.updateUserTrim] - ==> Parameters: 998989(String), 7(Integer)
2016-11-21 15:23:00,290 [main] DEBUG [/.updateUserTrim] - <==    Updates: 1

--------------------------------------------------
测试foreach 标签

+----+----------+----------+
| id | username | password |
+----+----------+----------+
|  2 | 慕容复   | 666666   |
|  4 | 段誉     | 122435   |
|  5 | 虚竹     | 43534    |
|  7 | 木婉清   | 998989   |
+----+----------+----------+
List<Integer> list = new ArrayList<>();
list.add(1);
list.add(2);
list.add(5);
List<User> userlist = sqlSession.selectList("selectUserforeach",list);

2016-11-21 16:01:29,184 [main] DEBUG [/.selectUserforeach] - ==>  Preparing: SELECT * FROM tb_user WHERE id IN ( ? , ? , ? )
2016-11-21 16:01:29,210 [main] DEBUG [/.selectUserforeach] - ==> Parameters: 1(Integer), 2(Integer), 5(Integer)
2016-11-21 16:01:29,223 [main] DEBUG [/.selectUserforeach] - <==      Total: 2
User [id=2, username=慕容复, password=666666]
User [id=5, username=虚竹, password=43534]

查询

<select>

参数

id  在这个模式下唯一的标识符，可被其它语句引用

parameterType   传给此语句的参数的完整类名或别名

resultType  语句返回值类型的整类名或别名。注意，如果是集合，那么这里填写的是集合的项的整类名或别名，而不是集合本身的类名。（resultType 与resultMap 不能并用）

resultMap   引用的外部resultMap 名。结果集映射是MyBatis 中最强大的特性。许多复杂的映射都可以轻松解决。（resultType 与resultMap 不能并用）

flushCache  如果设为true，则会在每次语句调用的时候就会清空缓存。select 语句默认设为false

useCache    如果设为true，则语句的结果集将被缓存。select 语句默认设为false

timeout 设置驱动器在抛出异常前等待回应的最长时间，默认为不设值，由驱动器自己决定

fetchSize   设置一个值后，驱动器会在结果集数目达到此数值后，激发返回，默认为不设值，由驱动器自己决定

statementType   statement，preparedstatement，callablestatement。预准备语句、可调用语句。可选值为(STATEMENT/PREPARED/CALLABLE),默认为PREPARED

resultSetType   forward_only，scroll_sensitive，scroll_insensitive
只转发，滚动敏感，不区分大小写的滚动，可选值(FORWARD_ONLY/SCROLL_SENSITIVE/SCROLL_INSENSITIVE)

事务处理

...
<environment id="development">
<transactionManager type="JDBC">

</transactionManager>
</environment>
...

SqlSession sqlSession = sqlSessionFactory.openSession(false);
//默认为false
try {
User one = new User();
one.setUsername("author01");
one.setPassword("43534");
//存入数据库之后，id值自动生成
sqlSession.insert("insertUser",one);
System.out.println("新加入的user id为"+one.getId());

Author au = new Author();
au.setUser(one);
au.setRealName("金庸");
au.setIDCard("360060040604064");

sqlSession.insert("insertAuthor333",au);
sqlSession.commit();
} catch (Exception e) {
e.printStackTrace();
//事务回滚
sqlSession.rollback();
}finally {
sqlSession.close();
}

Mybatis 异常和错误

PersistenceException

org.apache.ibatis.exceptions.PersistenceException:
### Error building SqlSession.
### Cause: org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: org.xml.sax.SAXParseException; lineNumber: 31; columnNumber: 105; 对实体 "useSSL" 的引用必须以 ';' 分隔符结尾。

<property name="url" value="jdbc:mysql://127.0.0.1:3306/db_mybatis?characterEncoding=utf8&useSSL=true"/>

<property name="url" value="jdbc:mysql://127.0.0.1:3306/db_mybatis?characterEncoding=utf8&useSSL=true"/>

org.apache.ibatis.exceptions.PersistenceException:
### Error building SqlSession.
### The error may exist in com/jxust/config/sqlxml/User.xml
### Cause: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. Cause: java.lang.IllegalArgumentException: Mapped Statements collection already contains value for /.hashmapselect

<!--  HashMap查询 -->
<select id="hashmapselect" resultType="User" parameterType="hashmap">
SELECT * FROM   tb_user WHERE username=#{username} AND password=#{password}
</select>
<!-- 对象查询 -->
<select id="hashmapselect" resultType="User" parameterType="User">
SELECT * FROM   tb_user WHERE username=#{username} AND password=#{password}
</select>

IllegalArgumentException

Caused by: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for

List<User> list = sqlSession.selectList("");

鉴别器

<discriminator javaType="" column="">
<case value="">
....
</case>
</discriminator>

<discriminator javaType="" column="">
<case value="1">
<result property="husband" column="husband"
</case>
case value="2">
<result property="wife" column="wife"
</case>
</discriminator>

Class GenneralClass extends UserClass //普通会员，等级为1
Class SeniorClass extends UserClass //高级会员，等级为2
Class VIPClass extends UserClass //VIP会员，等级为3