OpenCV 感興趣區域ROI和logo新增技術
阿新 • • 發佈：2020-12-23
Mybatis
依賴
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.47</version>
</dependency>
<dependency #mybatis配置檔案
<?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">
<!--核心配置檔案-->
<configuration>
<properties resource="db.properties"/>
<!--配置日誌檔案log4j-->
<!-- <settings>
<setting name="logImpl" value="LOG4J"/>
</settings>-->
<!--可以給實體類起別名，還可以通過掃掃描包來 -->
<typeAliases>
<package name="com.kuang.pojo"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${driver}"/>
<property name="url" value="${url}"/>
<property name="username" value="${username}"/>
<property name="password" value="${password}"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper class="com.kuang.dao.TeacherMapper"/>
<mapper class="com.kuang.dao.StudentMapper"/>
</mappers>
</configuration>
##其他配置
<!--配置日誌檔案log4j-->
<!-- <settings>
<setting name="logImpl" value="LOG4J"/>
</settings>-->
<!--可以給實體類起別名，還可以通過掃掃描包來 -->
<!--是否開啟駝峰命名自動對映，即從經典資料庫列名 A_COLUMN 對映到經典 Java 屬性名 aColumn。-->
<settings>
<setting name="mapUnderscoreToCamelCase" value="true"/>
</settings>
<typeAliases>
<package name="com.kuang.pojo"/>
</typeAliases>
##工具類
public class MybatisUtils {
private static SqlSessionFactory sqlSessionFactory;
static {
try {
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
} catch (IOException e) {
e.printStackTrace();
}
}
public static SqlSession getSession(){
return sqlSessionFactory.openSession();
}
}
##一對多和多對一的interface
##一對多Mapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--核心配置檔案-->
<mapper namespace="com.kuang.dao.TeacherMapper">
<!--按照結果巢狀查詢-->
<select id="getTeacher2" resultMap="TeacherStudent">
select s.id sid,s.name sname,t.id tid,t.name tname
from student s,teacher t
where s.tid=t.id and t.id=#{tid}
</select>
<resultMap id="TeacherStudent" type="Teacher">
<result property="id" column="tid"/>
<result property="name" column="tname"/>
<collection property="students" ofType="Student">
<result property="id" column="sid"/>
<result property="name" column="sname"/>
<result property="tid" column="tid"/>
</collection>
</resultMap>
<!--複雜屬性的對映，我們需要單獨處理 物件:association javaType=""指定屬性的型別
集合collection 使用ofType=""獲取集合中的泛型資訊-->
<!--=====================================================-->
<!--按照查詢巢狀查詢-->
<select id="getTeacher3" resultMap="TeacherStudent2">
select * from mabatis.teacher where id=#{tid}
</select>
<resultMap id="TeacherStudent2" type="Teacher">
<collection property="students" javaType="ArrayList" ofType="Student" select="getStudentByTeacherId" column="id"/>
</resultMap>
<select id="getStudentByTeacherId" resultType="Student">
select * from mabatis.student where tid=#{tid}
</select>
</mapper>
##多對一Mapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--核心配置檔案-->
<mapper namespace="com.kuang.dao.StudentMapper">
<!--按照結果巢狀處理-->
<select id="getStudent2" resultMap="StudentTeacher2">
select s.id sid,s.name sname,t.id tid,t.name tname
from student s,teacher t
where s.tid=t.id
</select>
<resultMap id="StudentTeacher2" type="Student">
<association property="id" column="sid"/>
<association property="name" column="sname"/>
<association property="teacher" javaType="Teacher">
<result property="name" column="tname"/>
<result property="id" column="tid"/>
</association>
</resultMap>
<!--=======================================================================-->
<!--按照查詢巢狀處理-->
<select id="getStudent" resultMap="StudentTeacher">
select * from student
</select>
<resultMap id="StudentTeacher" type="Student">
<result property="id" column="id"/>
<result property="name" column="name"/>
<association property="teacher" column="tid" javaType="Teacher" select="getTeacher"/>
</resultMap>
<select id="getTeacher" resultType="Teacher">
select * from teacher where id=#{id}
</select>
</mapper>
##動態sql
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.kuang.dao.BlogMapper">
<insert id="addBook" parameterType="blog">
insert into mabatis.blog(id, title, author, create_time, views)
values (#{id}, #{title}, #{author}, #{createTime}, #{views})
</insert>
<select id="queryBlogIf" parameterType="map" resultType="Blog">
select * from mabatis.blog
<where>
<if test="title != null">
and title=#{title}
</if>
<if test="author != null">
and author=#{author}
</if>
</where>
</select>
<update id="updateBlog" parameterType="map">
update mabatis.blog
<set>
<if test="title != null">
title=#{title},
</if>
<if test="author != null">
author=#{author},
</if>
</set>
where id=#{id}
</update>
<select id="queryBlogForeach" parameterType="map" resultType="Blog">
select * from mabatis.blog
<where>
<foreach collection="ids" item="id" open="and (" close=")" separator="or">
id = #{id}
</foreach>
</where>
</select>
</mapper>
##測試類
@Test
public void queryBlogIf(){
SqlSession session = MybatisUtils.getSession();
BlogMapper mapper = session.getMapper(BlogMapper.class);
HashMap map = new HashMap();
//map.put("author","狂神說4444");
map.put("title","java");
//map.put("id","46b1c7ec3ffa47eb90638d53f241baa6");
// map.put("author","狂神說");
//mapper.updateBlog(map);
List<Blog> blogs = mapper.queryBlogIf(map);
for (Blog blog : blogs) {
System.out.println(blog);
}
session.close();
}