MyBatis中XML 映射文件中常見的標簽說明

<select id="selectPerson" parameterType="int" resultType="hashmap">
   SELECT * FROM PERSON WHERE ID = #{id}
 </select>

// 近似的 JDBC 代碼，非 MyBatis 代碼...
 String selectPerson = "SELECT * FROM PERSON WHERE ID=?";
 PreparedStatement ps = conn.prepareStatement(selectPerson);
 ps.setInt(1,id);
 <select
   id="selectPerson"
   parameterType="int"
   parameterMap="deprecated"
   resultType="hashmap"
   resultMap="personResultMap"
   flushCache="false"
   useCache="true"
   timeout="10"
   fetchSize="256"
   statementType="PREPARED"
   resultSetType="FORWARD_ONLY">

<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">

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

 <selectKey resultType="java.lang.Long" order="AFTER" keyProperty="id">
   SELECT LAST_INSERT_ID() AS id
 </selectKey>

<sql id="userColumns"> ${alias}.id,${alias}.username,${alias}.password </sql>
 <select id="selectUsers" resultType="map">
   select
     <include refid="userColumns"><property name="alias" value="t1"/></include>,
     <include refid="userColumns"><property name="alias" value="t2"/></include>
   from some_table t1
     cross join some_table t2
 </select>

<select id="selectUsers" resultType="com.someapp.model.User">
   select id, username, hashedPassword
   from some_table
   where id = #{id}
 </select>

 <resultMap id="userResultMap" type="User">
   <id property="id" column="user_id" />
   <result property="username" column="user_name"/>
   <result property="password" column="hashed_password"/>
 </resultMap>
 ​
 <select id="selectUsers" resultMap="userResultMap">
   select user_id, user_name, hashed_password
   from some_table
   where id = #{id}
 </select>

 <id property="id" column="post_id"/>
 <result property="subject" column="post_subject"/>

 <cache
   eviction="FIFO"
   flushInterval="60000"
   size="512"
   readOnly="true"/>

 <cache type="com.domain.something.MyCustomCache"/>

 public interface Cache {
   String getId();
   int getSize();
   void putObject(Object key, Object value);
   Object getObject(Object key);
   boolean hasKey(Object key);
   Object removeObject(Object key);
   void clear();
 }

 <select id="findActiveBlogWithTitleLike"
      resultType="Blog">
   SELECT * FROM BLOG
   WHERE state = ‘ACTIVE'
   <if test="title != null">
     AND title like #{title}
   </if>
 </select>

 <select id="findActiveBlogLike"
      resultType="Blog">
   SELECT * FROM BLOG WHERE state = ‘ACTIVE'
   <if test="title != null">
     AND title like #{title}
   </if>
   <if test="author != null and author.name != null">
     AND author_name like #{author.name}
   </if>
 </select>

 <select id="findActiveBlogLike"
      resultType="Blog">
   SELECT * FROM BLOG WHERE state = ‘ACTIVE'
   <choose>
     <when test="title != null">
       AND title like #{title}
     </when>
     <when test="author != null and author.name != null">
       AND author_name like #{author.name}
     </when>
     <otherwise>
       AND featured = 1
     </otherwise>
   </choose>
 </select>

 <select id="findActiveBlogLike"
      resultType="Blog">
   SELECT * FROM BLOG
   <where>
     <if test="state != null">
          state = #{state}
     </if>
     <if test="title != null">
         AND title like #{title}
     </if>
     <if test="author != null and author.name != null">
         AND author_name like #{author.name}
     </if>
   </where>
 </select>

 <trim prefix="WHERE" prefixOverrides="AND |OR ">
   ...
 </trim>

 <update id="updateAuthorIfNecessary">
   update Author
     <set>
       <if test="username != null">username=#{username},</if>
       <if test="password != null">password=#{password},</if>
       <if test="email != null">email=#{email},</if>
       <if test="bio != null">bio=#{bio}</if>
     </set>
   where id=#{id}
 </update>

 <trim prefix="SET" suffixOverrides=",">
   ...
 </trim>

 <select id="selectPostIn" resultType="domain.blog.Post">
   SELECT *
   FROM POST P
   WHERE ID in
   <foreach item="item" index="index" collection="list"
       open="(" separator="," close=")">
         #{item}
   </foreach>
 </select>

 <select id="selectBlogsLike" resultType="Blog">
   <bind name="pattern" value="'%' + _parameter.getTitle() + '%'" />
   SELECT * FROM BLOG
   WHERE title LIKE #{pattern}
 </select>