<!--
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