一、mybatis简介
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对结果集的检索封装。
mybatis可以使用简单的xml或注解用于配置和原始映射，将接口和java的pojo（plain old java objects，普通的java对象）映射成数据库中的记录.
jdbc -> dbutils(自动封装) -> mybatis -> hibernate
mybatis是将sql写在xml中，然后去访问数据库。
二、mybatis快速入门
2.1.新建java项目
添加mybatis和mysql的驱动jar：mybatis-3.1.1.jar,mysql-connector-java-5.1.7-bin.jar
2.2.新建表
我要评论
create database mybatis;
use mybatis;
create table users(id int primary key auto_increment, name varchar(20), age int);
insert into users (name,age) values('tom',12);
insert into users (name, age) values('jack',11);
2.3.添加mybatis的配置文件conf.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> <environments default="development"> <environment id="development"> <transactionmanager type="jdbc" /> <datasource type="pooled"> <property name="driver" value="com.mysql.jdbc.driver" /> <property name="url" value="jdbc:mysql://localhost:3306/mybatis" /> <property name="username" value="root" /> <property name="password" value="root" /> </datasource> </environment> </environments> </configuration>
2.4.定义表对应的实体类
public class user {
private int id;
private string name;
private int age;
//get,set方法
}
2.5.定义操作users表的sql映射文件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.atguigu.mybatis_test.test1.usermapper">
<select id="getuser" parametertype="int"
resulttype="com.atguigu.mybatis_test.test1.user">
select * from users where id=#{id}
</select>
</mapper>
2.6.在conf.xml文件中注册usermapper.xml文件
<mappers> <mapper resource="com/atguigu/mybatis_test/test1/usermapper.xml"/> </mappers>
2.7.编写测试代码：执行定义的select语句
public class test {
public static void main(string[] args) throws ioexception {
string resource = "conf.xml";
//加载mybatis的配置文件（它也加载关联的映射文件）
reader reader = resources.getresourceasreader(resource);
//构建sqlsession的工厂
sqlsessionfactory sessionfactory = new sqlsessionfactorybuilder().build(reader);
//创建能执行映射文件中sql的sqlsession
sqlsession session = sessionfactory.opensession();
//映射sql的标识字符串
string statement = "com.atguigu.mybatis.bean.usermapper"+".selectuser";
//执行查询返回一个唯一user对象的sql
user user = session.selectone(statement, 1);
system.out.println(user);
}
}
三、操作users表的crud
3.1.xml的实现
3.1.1.定义sql映射xml文件：
<insert id="insertuser" parametertype="com.atguigu.ibatis.bean.user">
insert into users(name, age) values(#{name}, #{age});
</insert>
<delete id="deleteuser" parametertype="int">
delete from users where id=#{id}
</delete>
<update id="updateuser" parametertype="com.atguigu.ibatis.bean.user">
update users set name=#{name},age=#{age} where id=#{id}
</update>
<select id="selectuser" parametertype="int" resulttype="com.atguigu.ibatis.bean.user">
select * from users where id=#{id}
</select>
<select id="selectallusers" resulttype="com.atguigu.ibatis.bean.user">
select * from users
</select>
3.1.2.在config.xml中注册这个映射文件
<mapper resource=" com/atguigu/ibatis/bean/usermapper.xml"/>
3.1.3.在dao中调用
public user getuserbyid(int id) {
sqlsession session = sessionfactory.opensession();
user user = session.selectone(uri+".selectuser", id);
return user;
}
3.2.注解的实现
3.2.1.定义sql映射的接口
public interface usermapper {
@insert("insert into users(name, age) values(#{name}, #{age})")
public int insertuser(user user);
@delete("delete from users where id=#{id}")
public int deleteuserbyid(int id);
@update("update users set name=#{name},age=#{age} where id=#{id}")
public int updateuser(user user);
@select("select * from users where id=#{id}")
public user getuserbyid(int id);
@select("select * from users")
public list<user> getalluser();
}
3.2.2.在config中注册这个映射接口
<mapper class="com.atguigu.ibatis.crud.ano.usermapper"/>
3.2.3.在dao中调用
public user getuserbyid(int id) {
sqlsession session = sessionfactory.opensession();
usermapper mapper = session.getmapper(usermapper.class);
user user = mapper.getuserbyid(id);
return user;
}
四、几个可以优化的地方
4.1.连接数据库的配置可以单独放在一个properties文件中。
## db.properties<br>
<properties resource="db.properties"/>
<property name="driver" value="${driver}" />
<property name="url" value="${url}" />
<property name="username" value="${username}" />
<property name="password" value="${password}" />
4.2.为实体类定义别名,简化sql映射xml文件中的引用
<typealiases> <typealias type="com.atguigu.ibatis.bean.user" alias="_user"/> </typealiases>
4.3.可以在src下加入log4j的配置文件,打印日志信息
1. 添加jar:
log4j-1.2.16.jar
2.1. log4j.properties(方式一)
log4j.properties， log4j.rootlogger=debug, console #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.java.sql.resultset=info log4j.logger.org.apache=info log4j.logger.java.sql.connection=debug log4j.logger.java.sql.statement=debug log4j.logger.java.sql.preparedstatement=debug
2.2. log4j.xml(方式二)
<?xml version="1.0" encoding="utf-8" ?>
<!doctype log4j:configuration system "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
<appender name="stdout" class="org.apache.log4j.consoleappender">
<layout class="org.apache.log4j.patternlayout">
<param name="conversionpattern"
value="%-5p %d{mm-dd hh:mm:ss,sss} %m (%f:%l) \n" />
</layout>
</appender>
<logger name="java.sql">
<level value="debug" />
</logger>
<logger name="org.apache.ibatis">
<level value="debug" />
</logger>
<root>
<level value="debug" />
<appender-ref ref="stdout" />
</root>
</log4j:configuration>
五、解决字段名与实体类属性名不相同的冲突
5.1.准备表和字段
create table orders(
order_id int primary key auto_increment,
order_no varchar(20),
order_price float
);
insert into orders(order_no, order_price) values('aaaa', 23);
insert into orders(order_no, order_price) values('bbbb', 33);
insert into orders(order_no, order_price) values('cccc', 22);
5.2.定义实体类
public class order {
private int id;
private string orderno;
private float price;
}
5.3.实现getorderbyid(id)的查询：
方式一: 通过在sql语句中定义别名
<select id="selectorder" parametertype="int" resulttype="_order">
select order_id id, order_no orderno,order_price price from orders where order_id=#{id}
</select>
方式二: 通过<resultmap>
<select id="selectorderresultmap" parametertype="int" resultmap="orderresultmap">
select * from orders where order_id=#{id}
</select>
<resultmap type="_order" id="orderresultmap">
<id property="id" column="order_id"/>
<result property="orderno" column="order_no"/>
<result property="price" column="order_price"/>
</resultmap>
六、实现关联表查询
6.1.一对一关联
6.1.1.提出需求
根据班级id查询班级信息(带老师的信息)
6.1.2.创建表和数据
create table teacher(
t_id int primary key auto_increment,
t_name varchar(20)
);
create table class(
c_id int primary key auto_increment,
c_name varchar(20),
teacher_id int
);
alter table class add constraint fk_teacher_id foreign key (teacher_id) references teacher(t_id);
insert into teacher(t_name) values('ls1');
insert into teacher(t_name) values('ls2');
insert into class(c_name, teacher_id) values('bj_a', 1);
insert into class(c_name, teacher_id) values('bj_b', 2);
6.1.3.定义实体类：
public class teacher {
private int id;
private string name;
}
public class classes {
private int id;
private string name;
private teacher teacher;
}
6.1.4.定义sql映射文件classmapper.xml
<!--
方式一: 嵌套结果: 使用嵌套结果映射来处理重复的联合结果的子集
select * from class c, teacher t,student s where c.teacher_id=t.t_id and c.c_id=s.class_id and c.c_id=1
-->
<select id="getclass3" parametertype="int" resultmap="classresultmap3">
select * from class c, teacher t,student s where c.teacher_id=t.t_id and c.c_id=s.class_id and c.c_id=#{id}
</select>
<resultmap type="_classes" id="classresultmap3">
<id property="id" column="c_id"/>
<result property="name" column="c_name"/>
<association property="teacher" column="teacher_id" javatype="_teacher">
<id property="id" column="t_id"/>
<result property="name" column="t_name"/>
</association>
<!-- oftype指定students集合中的对象类型 -->
<collection property="students" oftype="_student">
<id property="id" column="s_id"/>
<result property="name" column="s_name"/>
</collection>
</resultmap>
<!--
方式二：嵌套查询：通过执行另外一个sql映射语句来返回预期的复杂类型
select * from class where c_id=1;
select * from teacher where t_id=1 //1 是上一个查询得到的teacher_id的值
select * from student where class_id=1 //1是第一个查询得到的c_id字段的值
-->
<select id="getclass4" parametertype="int" resultmap="classresultmap4">
select * from class where c_id=#{id}
</select>
<resultmap type="_classes" id="classresultmap4">
<id property="id" column="c_id"/>
<result property="name" column="c_name"/>
<association property="teacher" column="teacher_id" javatype="_teacher" select="getteacher2"></association>
<collection property="students" oftype="_student" column="c_id" select="getstudent"></collection>
</resultmap>
<select id="getteacher2" parametertype="int" resulttype="_teacher">
select t_id id, t_name name from teacher where t_id=#{id}
</select>
<select id="getstudent" parametertype="int" resulttype="_student">
select s_id id, s_name name from student where class_id=#{id}
</select>
6.1.5.测试
@test
public void testoo() {
sqlsession sqlsession = factory.opensession();
classes c = sqlsession.selectone("com.atguigu.day03_mybatis.test5.oomapper.getclass", 1);
system.out.println(c);
}
@test
public void testoo2() {
sqlsession sqlsession = factory.opensession();
classes c = sqlsession.selectone("com.atguigu.day03_mybatis.test5.oomapper.getclass2", 1);
system.out.println(c);
}
6.2.一对多关联
6.2.1.提出需求
根据classid查询对应的班级信息,包括学生,老师
6.2.2.创建表和数据：
create table student(
s_id int primary key auto_increment,
s_name varchar(20),
class_id int
);
insert into student(s_name, class_id) values('xs_a', 1);
insert into student(s_name, class_id) values('xs_b', 1);
insert into student(s_name, class_id) values('xs_c', 1);
insert into student(s_name, class_id) values('xs_d', 2);
insert into student(s_name, class_id) values('xs_e', 2);
insert into student(s_name, class_id) values('xs_f', 2);
6.2.3.定义实体类
public class student {
private int id;
private string name;
}
public class classes {
private int id;
private string name;
private teacher teacher;
private list<student> students;
}
6.2.4.定义sql映射文件classmapper.xml
<!--
方式一: 嵌套结果: 使用嵌套结果映射来处理重复的联合结果的子集
select * from class c, teacher t,student s where c.teacher_id=t.t_id and c.c_id=s.class_id and c.c_id=1
-->
<select id="getclass3" parametertype="int" resultmap="classresultmap3">
select * from class c, teacher t,student s where c.teacher_id=t.t_id and c.c_id=s.class_id and c.c_id=#{id}
</select>
<resultmap type="_classes" id="classresultmap3">
<id property="id" column="c_id"/>
<result property="name" column="c_name"/>
<association property="teacher" column="teacher_id" javatype="_teacher">
<id property="id" column="t_id"/>
<result property="name" column="t_name"/>
</association>
<!-- oftype指定students集合中的对象类型 -->
<collection property="students" oftype="_student">
<id property="id" column="s_id"/>
<result property="name" column="s_name"/>
</collection>
</resultmap>
<!--
方式二：嵌套查询：通过执行另外一个sql映射语句来返回预期的复杂类型
select * from class where c_id=1;
select * from teacher where t_id=1 //1 是上一个查询得到的teacher_id的值
select * from student where class_id=1 //1是第一个查询得到的c_id字段的值
-->
<select id="getclass4" parametertype="int" resultmap="classresultmap4">
select * from class where c_id=#{id}
</select>
<resultmap type="_classes" id="classresultmap4">
<id property="id" column="c_id"/>
<result property="name" column="c_name"/>
<association property="teacher" column="teacher_id" javatype="_teacher" select="getteacher2"></association>
<collection property="students" oftype="_student" column="c_id" select="getstudent"></collection>
</resultmap>
<select id="getteacher2" parametertype="int" resulttype="_teacher">
select t_id id, t_name name from teacher where t_id=#{id}
</select>
<select id="getstudent" parametertype="int" resulttype="_student">
select s_id id, s_name name from student where class_id=#{id}
</select>
6.2.5.测试
@test
public void testom() {
sqlsession sqlsession = factory.opensession();
classes c = sqlsession.selectone("com.atguigu.day03_mybatis.test5.oomapper.getclass3", 1);
system.out.println(c);
}
@test
public void testom2() {
sqlsession sqlsession = factory.opensession();
classes c = sqlsession.selectone("com.atguigu.day03_mybatis.test5.oomapper.getclass4", 1);
system.out.println(c);
}
七、动态sql与模糊查询
7.1.需求
实现多条件查询用户(姓名模糊匹配, 年龄在指定的最小值到最大值之间)。
7.2.准备数据库和表
create table d_user(
id int primary key auto_increment,
name varchar(10),
age int(3)
);
insert into d_user(name,age) values('tom',12);
insert into d_user(name,age) values('bob',13);
insert into d_user(name,age) values('jack',18);
7.3.conditionuser(查询条件实体类)
private string name;
private int minage;
private int maxage;
7.4.user表实体类
private int id; private string name; private int age;
7.5.usermapper.xml(映射文件)
<?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.atguigu.day03_mybatis.test6.usermapper">
<select id="getuser" parametertype="com.atguigu.day03_mybatis.test6.conditionuser" resulttype="com.atguigu.day03_mybatis.test6.user">
select * from d_user where age>=#{minage} and age<=#{maxage}
<if test='name!="%null%"'>and name like #{name}</if>
</select>
</mapper>
7.6.usertest(测试)
public class usertest {
public static void main(string[] args) throws ioexception {
reader reader = resources.getresourceasreader("conf.xml");
sqlsessionfactory sessionfactory = new sqlsessionfactorybuilder().build(reader);
sqlsession sqlsession = sessionfactory.opensession();
string statement = "com.atguigu.day03_mybatis.test6.usermapper.getuser";
list<user> list = sqlsession.selectlist(statement, new conditionuser("%a%", 1, 12));
system.out.println(list);
}
}
mybatis中可用的动态sql标签
八、调用存储过程
8.1.提出需求
查询得到男性或女性的数量, 如果传入的是0就女性否则是男性
8.2.准备数据库表和存储过程:
create table p_user(
id int primary key auto_increment,
name varchar(10),
sex char(2)
);
insert into p_user(name,sex) values('a',"男");
insert into p_user(name,sex) values('b',"女");
insert into p_user(name,sex) values('c',"男");
#创建存储过程(查询得到男性或女性的数量, 如果传入的是0就女性否则是男性)
delimiter $
create procedure mybatis.ges_user_count(in sex_id int, out user_count int)
begin
if sex_id=0 then
select count(*) from mybatis.p_user where p_user.sex='女' into user_count;
else
select count(*) from mybatis.p_user where p_user.sex='男' into user_count;
end if;
end
$
#调用存储过程
delimiter ;
set @user_count = 0;
call mybatis.ges_user_count(1, @user_count);
select @user_count;
8.3.创建表的实体类
public class user {
private string id;
private string name;
private string sex;
}
8.4.usermapper.xml
<mapper namespace="com.atguigu.mybatis.test7.usermapper"> <!-- 查询得到男性或女性的数量, 如果传入的是0就女性否则是男性 call mybatis.get_user_count(1, @user_count); --> <select id="getcount" statementtype="callable" parametermap="getcountmap"> call mybatis.get_user_count(?,?) </select> <parametermap type="java.util.map" id="getcountmap"> <parameter property="sex_id" mode="in" jdbctype="integer"/> <parameter property="user_count" mode="out" jdbctype="integer"/> </parametermap> </mapper>
8.5.测试
map<string, integer> parammap = new hashmap<>();
parammap.put("sex_id", 0);
session.selectone(statement, parammap);
integer usercount = parammap.get("user_count");
system.out.println(usercount);
九、mybatis缓存
9.1.理解mybatis缓存
正如大多数持久层框架一样，mybatis 同样提供了一级缓存和二级缓存的支持
1.一级缓存: 基于perpetualcache 的 hashmap本地缓存，其存储作用域为 session，当 session flush 或 close 之后，该session中的所有 cache 就将清空。
2. 二级缓存与一级缓存其机制相同，默认也是采用 perpetualcache，hashmap存储，不同在于其存储作用域为 mapper(namespace)，并且可自定义存储源，如 ehcache。
3. 对于缓存数据更新机制，当某一个作用域(一级缓存session/二级缓存namespaces)的进行了 c/u/d 操作后，默认该作用域下所有 select 中的缓存将被clear。
9.2.mybatis一级缓存
9.2.1.根据任务查询
根据id查询对应的用户记录对象。
9.2.2.准备数据库表和数据
create table c_user(
id int primary key auto_increment,
name varchar(20),
age int
);
insert into c_user(name, age) values('tom', 12);
insert into c_user(name, age) values('jack', 11);
9.2.3.创建表的实体类
public class user implements serializable{
private int id;
private string name;
private int age;
9.2.4.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.atguigu.mybatis.test8.usermapper">
<select id="getuser" parametertype="int" resulttype="_cuser">
select * from c_user where id=#{id}
</select>
<update id="updateuser" parametertype="_cuser">
update c_user set
name=#{name}, age=#{age} where id=#{id}
</update>
</mapper>
9.2.5.测试
/*
* 一级缓存: 也就session级的缓存(默认开启)
*/
@test
public void testcache1() {
sqlsession session = mybatisutils.getsession();
string statement = "com.atguigu.mybatis.test8.usermapper.getuser";
user user = session.selectone(statement, 1);
system.out.println(user);
/*
* 一级缓存默认就会被使用
*/
/*
user = session.selectone(statement, 1);
system.out.println(user);
*/
/*
1. 必须是同一个session,如果session对象已经close()过了就不可能用了
*/
/*
session = mybatisutils.getsession();
user = session.selectone(statement, 1);
system.out.println(user);
*/
/*
2. 查询条件是一样的
*/
/*
user = session.selectone(statement, 2);
system.out.println(user);
*/
/*
3. 没有执行过session.clearcache()清理缓存
*/
/*
session.clearcache();
user = session.selectone(statement, 2);
system.out.println(user);
*/
/*
4. 没有执行过增删改的操作(这些操作都会清理缓存)
*/
/*
session.update("com.atguigu.mybatis.test8.usermapper.updateuser",
new user(2, "user", 23));
user = session.selectone(statement, 2);
system.out.println(user);
*/
}
9.3.mybatis二级缓存
9.3.1.添加一个<cache>在usermapper.xml中
<mapper namespace="com.atguigu.mybatis.test8.usermapper"> <cache/>
9.3.2.测试
/*
* 测试二级缓存
*/
@test
public void testcache2() {
string statement = "com.atguigu.mybatis.test8.usermapper.getuser";
sqlsession session = mybatisutils.getsession();
user user = session.selectone(statement, 1);
session.commit();
system.out.println("user="+user);
sqlsession session2 = mybatisutils.getsession();
user = session2.selectone(statement, 1);
session.commit();
system.out.println("user2="+user);
}
9.3.3.补充说明
1. 映射语句文件中的所有select语句将会被缓存。
2. 映射语句文件中的所有insert，update和delete语句会刷新缓存。
3. 缓存会使用least recently used（lru，最近最少使用的）算法来收回。
4. 缓存会根据指定的时间间隔来刷新。
5. 缓存会存储1024个对象
<cache eviction="fifo" //回收策略为先进先出 flushinterval="60000" //自动刷新时间60s size="512" //最多缓存512个引用对象 readonly="true"/> //只读
十、spring集成mybatis
10.1.添加jar
【mybatis】
mybatis-3.2.0.jar
mybatis-spring-1.1.1.jar
log4j-1.2.17.jar
【spring】
spring-aop-3.2.0.release.jar
spring-beans-3.2.0.release.jar
spring-context-3.2.0.release.jar
spring-core-3.2.0.release.jar
spring-expression-3.2.0.release.jar
spring-jdbc-3.2.0.release.jar
spring-test-3.2.4.release.jar
spring-tx-3.2.0.release.jar
aopalliance-1.0.jar
cglib-nodep-2.2.3.jar
commons-logging-1.1.1.jar
【mysql驱动包】
mysql-connector-java-5.0.4-bin.jar
10.2.数据库表
create table s_user( user_id int auto_increment primary key, user_name varchar(30), user_birthday date, user_salary double )
10.3.实体类：user
public class user {
private int id;
private string name;
private date birthday;
private double salary;
//set,get方法
}
10.4.dao接口: usermapper (xxxmapper)
public interface usermapper {
void save(user user);
void update(user user);
void delete(int id);
user findbyid(int id);
list<user> findall();
}
10.5.sql映射文件: usermapper.xml(与接口忽略大小写同名)
<?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.atguigu.mybatis.test9.usermapper">
<resultmap type="user" id="userresult">
<result column="user_id" property="id"/>
<result column="user_name" property="name"/>
<result column="user_birthday" property="birthday"/>
<result column="user_salary" property="salary"/>
</resultmap>
<!-- 取得插入数据后的id -->
<insert id="save" keycolumn="user_id" keyproperty="id" usegeneratedkeys="true">
insert into s_user(user_name,user_birthday,user_salary)
values(#{name},#{birthday},#{salary})
</insert>
<update id="update">
update s_user
set user_name = #{name},
user_birthday = #{birthday},
user_salary = #{salary}
where user_id = #{id}
</update>
<delete id="delete">
delete from s_user
where user_id = #{id}
</delete>
<select id="findbyid" resultmap="userresult">
select *
from s_user
where user_id = #{id}
</select>
<select id="findall" resultmap="userresult">
select *
from s_user
</select>
</mapper>
10.6.spring的配置文件: beans.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:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemalocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd"> <!-- 1. 数据源 : drivermanagerdatasource --> <bean id="datasource" class="org.springframework.jdbc.datasource.drivermanagerdatasource"> <property name="driverclassname" value="com.mysql.jdbc.driver"/> <property name="url" value="jdbc:mysql://localhost:3306/mybatis"/> <property name="username" value="root"/> <property name="password" value="root"/> </bean> <!-- 2. mybatis的sqlsession的工厂: sqlsessionfactorybean datasource / typealiasespackage --> <bean id="sqlsessionfactory" class="org.mybatis.spring.sqlsessionfactorybean"> <property name="datasource" ref="datasource"/> <property name="typealiasespackage" value="com.atuigu.spring_mybatis2.domain"/> </bean> <!-- 3. mybatis自动扫描加载sql映射文件 : mapperscannerconfigurer sqlsessionfactory / basepackage --> <bean class="org.mybatis.spring.mapper.mapperscannerconfigurer"> <property name="basepackage" value="com.atuigu.spring_mybatis2.mapper"/> <property name="sqlsessionfactory" ref="sqlsessionfactory"/> </bean> <!-- 4. 事务管理 : datasourcetransactionmanager --> <bean id="txmanager" class="org.springframework.jdbc.datasource.datasourcetransactionmanager"> <property name="datasource" ref="datasource"/> </bean> <!-- 5. 使用声明式事务 --> <tx:annotation-driven transaction-manager="txmanager" /> </beans>
10.7.mybatis的配置文件: 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> <!-- spring整合mybatis后，这个配置文件基本可以不要了--> <!-- 设置外部配置文件 --> <!-- 设置类别名 --> <!-- 设置数据库连接环境 --> <!-- 映射文件 --> </configuration>
10.8.测试
@runwith(springjunit4classrunner.class) //使用springtest测试框架
@contextconfiguration("/beans.xml") //加载配置
public class smtest {
@autowired //注入
private usermapper usermapper;
@test
public void save() {
user user = new user();
user.setbirthday(new date());
user.setname("marry");
user.setsalary(300);
usermapper.save(user);
system.out.println(user.getid());
}
@test
public void update() {
user user = usermapper.findbyid(2);
user.setsalary(2000);
usermapper.update(user);
}
@test
public void delete() {
usermapper.delete(3);
}
@test
public void findbyid() {
user user = usermapper.findbyid(1);
system.out.println(user);
}
@test
public void findall() {
list<user> users = usermapper.findall();
system.out.println(users);
}
}
以上所述是小编给大家介绍的mybatis快速入门(简明浅析易懂)，希望对大家有所帮助
如对本文有疑问， 点击进行留言回复！！
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