MyBatis如何防止SQL注入

 1 <select id="selectBackGoodsDetail" resultType="java.util.Map">
 2     SELECT sum(a.item_num) backGoodsNum,a.item_price backGoodsPrice,
 3     sum(a.item_num * a.item_price) backGoodsSumPrice,
 4     b.barcode,b.name itemName,b.weight,c.name itemCategoryName
 5     FROM back_goods_detail a
 6     LEFT JOIN item b ON a.item_id=b.id
 7     LEFT JOIN item_category c ON b.item_category_id =c.id
 8     <where>
 9         <if test="backGoodsId!=null">
10             a.back_goods_id = #{backGoodsId}
11         </if>
12         <if test="itemCategoryId!=null">
13             AND b.item_category_id = #{itemCategoryId}
14         </if>
15         <if test="searchKey!= null">
16             AND (b.sequence LIKE CONCAT(‘%‘, #{searchKey}, ‘%‘)
17             OR b.name LIKE CONCAT(‘%‘, #{searchKey}, ‘%‘)
18             OR b.barcode LIKE CONCAT(‘%‘,#{searchKey},‘%‘))
19         </if>
20     </where>
21     GROUP BY a.item_id
22     LIMIT #{pageStart},#{pageNum}
23 </select>