IBATIS动态查询语句

<!--
在ibatis中使用安全的拼接语句,动态查询
ibatis比JDBC的优势之一,安全高效
说明文字在注释中
-->


  <select id="selectAllProducts" parameterClass="Product" resultMap="ProductResult">
     select id,note from Product
       <dynamic prepend="WHERE">
       <!-- isNotNull判断参数是否存在,Integer类型 -->
            <isNotNull property="id">
                <!-- isGreaterThan判断参数是否大于compareValue,isGreaterEquals是大于等于 -->
                <isGreaterThan prepend=" and " property="id" compareValue="0">
                 id = #id#
                </isGreaterThan>
            </isNotNull>
            <!-- isNotEmpty判断字串不为空,isEmpty可以判断字串为空 -->
            <isNotEmpty prepend=" and " property="note">
            <!-- 模糊查询不能用#,#在是用prepareStatement的?插入参数,$是文本替换 -->
             note like '%$note$%'
            </isNotEmpty>
        </dynamic>
  </select>
 
用Map传参数
 
  <select id="selectAllProducts" parameterClass="java.util.HashMap" resultMap="ProductResult">
     select id,note from Product
       <dynamic prepend="WHERE">
       <!-- isPropertyAvailable判断属性是否有效 -->
          <isPropertyAvailable property="id">
            <isNotNull property="id">
                <!-- isLessThan判断参数是否小于compareValue,isLessEquals是小于等于 -->
                <isLessThan prepend=" and " property="id" compareValue="10">
                 id = #id#
                </isLessThan>
            </isNotNull>
          </isPropertyAvailable>
        </dynamic>
  </select>
<!--------------------------------------------------------------------几个常用属性-->

<isPropertyAvailable> 属性是存在
<isNotPropertyAvailable> 属性不存在
<isNull> 属性值是null
<isEmpty> 判断Collection.size<1或String.length()<1
<isEqual> 等于
<isNotEqual> 不等于
<isGreaterThan> 大于
<isGreaterEqual> 大于等于
<isLessThan> 小于
<isLessEqual> 小于等于