4 - map映射器 - 基础 - 表名.xml

mapping 的 Info.xml 例子 <select> 查

src/main/resources/com/artchips/mapper/Info.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.artchips.bean.Info">
    <!-- 
        根据id查询Info信息
        resultType的属性值简写，可以参见mybatis-config.xml文件typeAliase属性说明
        如果typeAliase属性没有做特定配置，那么这里的resultType的属性值就需要写全称
     -->
    <select id="selectAllInfo" parameterType="int" resultType="com.artchips.bean.Info">
        select * from Info 
    </select>
</mapper>

< mapper >:XML的根元素，属性namespace定义了当前xml的命名空间

< select >元素：定义的一个SELECT查询。

• id属性：定义了当前SELECT查询的唯一一个id，程序调用这个id的属性值；
• parameterType接受一个 int（或 Integer）类型的参数
• resultType：定义了当前查询的返回值类型，此处指的是实体类Info。

id=”selectPerson”
parameterType=”int”
parameterMap=”deprecated”
resultType=”hashmap”
resultMap=”personResultMap”
flushCache=”false”
useCache=”true”
timeout=”10”
fetchSize=”256”
statementType=”PREPARED”
resultSetType=”FORWARD_ONLY”

<insert>增 <update> 改 <delete>删

<insert
  id="insertAuthor"
  parameterType="domain.blog.Author"
  flushCache="true"
  statementType="PREPARED"
  keyProperty=""
  keyColumn=""
  useGeneratedKeys=""
  timeout="20">
<update
  id="updateAuthor"
  parameterType="domain.blog.Author"
  flushCache="true"
  statementType="PREPARED"
  timeout="20">
<delete
  id="deleteAuthor"
  parameterType="domain.blog.Author"
  flushCache="true"
  statementType="PREPARED"
  timeout="20">

<insert id="insertAuthor">
  insert into Author (id,username,password,email,bio)
  values (#{id},#{username},#{password},#{email},#{bio})
</insert>
<update id="updateAuthor">
  update Author set
    username = #{username},
    password = #{password},
    email = #{email},
    bio = #{bio}
  where id = #{id}
</update>
<delete id="deleteAuthor">
  delete from Author where id = #{id}
</delete>

多行插入foreach

<insert id="insertAuthor" useGeneratedKeys="true"
    keyProperty="id">
  insert into Author (username, password, email, bio) values
  <foreach item="item" collection="list" separator=",">
    (#{item.username}, #{item.password}, #{item.email}, #{item.bio})
  </foreach>
</insert>

selectKey

<selectKey
  keyProperty="id"
  resultType="int"
  order="BEFORE"
  statementType="PREPARED">