MyBatis CRUD 常用动态 SQL 标签整理

<select id="selectUser" parameterType="map" resultType="User">
  SELECT * FROM user
  <where>
    <if test="name != null and name != ''">
      name = #{name}
    </if>
    <if test="age != null">
      AND age = #{age}
    </if>
  </where>
</select>

<select id="getUser" parameterType="map" resultType="User">
  SELECT * FROM user
  <where>
    <choose>
      <when test="id != null">
        id = #{id}
      </when>
      <when test="name != null">
        name = #{name}
      </when>
      <otherwise>
        1 = 1
      </otherwise>
    </choose>
  </where>
</select>

<where>
  <if test="name != null">name = #{name}</if>
  <if test="age != null">AND age = #{age}</if>
</where>

<update id="updateUser" parameterType="User">
  UPDATE user
  <set>
    <if test="name != null">name = #{name},</if>
    <if test="age != null">age = #{age},</if>
  </set>
  WHERE id = #{id}
</update>

<insert id="batchInsert" parameterType="list">
  INSERT INTO user (name, age) VALUES
  <foreach collection="list" item="user" separator=",">
    (#{user.name}, #{user.age})
  </foreach>
</insert>

<select id="selectByIds" parameterType="list" resultType="User">
  SELECT * FROM user WHERE id IN
  <foreach collection="list" item="id" open="(" separator="," close=")">
    #{id}
  </foreach>
</select>

<update id="updateUser" parameterType="User">
  UPDATE user
  <trim prefix="SET" suffixOverrides=",">
    <if test="name != null">name = #{name},</if>
    <if test="age != null">age = #{age},</if>
  </trim>
  WHERE id = #{id}
</update>