高级查询，分页

高级查询，分页：

1：service层：

代码：

  @Override
    public QueryLimitPageObj queryLimitPage(ProductQueryObj productQueryObj) {
        QueryLimitPageObj queryLimitPageObj = new QueryLimitPageObj();
      //查询列表
        List<Product> products = productDao.chooseQuery(productQueryObj);
        queryLimitPageObj.setData(products);
        //当前页
        Integer currentPage = productQueryObj.getCurrentPage();
        queryLimitPageObj.setCurrentPage(currentPage);
        //每页显示条数
        Integer pageSize = productQueryObj.getPageSize();
        queryLimitPageObj.setPageSize(pageSize);
        //总条数
        int totalNum = productDao.getTotalNum(productQueryObj);
        queryLimitPageObj.setTotalNum(totalNum);
        //总页数
         queryLimitPageObj.setTotalPage((totalNum + pageSize - 1)/ pageSize);
        return queryLimitPageObj;
    }

2：封装分页对象：

3.封装高级查询对象：

sql :

  

    <sql id="queryCommon">
        <where>
            <if test="productName!=null and productName!=''">
                AND product_name=#{productName}
            </if>
            <if test="stockNum!=null and stockNum!=''">
                AND stock_num=#{stockNum}
            </if>
            <if test="minSalePrice!=null and minSalePrice!=''">
                AND sale_price>=#{minSalePrice}
            </if>
            <if test="maxSalePrice!=null and maxSalePrice!=''">
                AND sale_price &lt;= #{maxSalePrice}
            </if>
        </where>
    </sql>


    <select id="chooseQuery" parameterType="com.floor.shop.query.ProductQueryObj"
            resultType="com.floor.shop.model.Product">
        SELECT id,product_name productName ,sale_price salePrice,stock_num stockNum,`type` type FROM product
        <include refid="queryCommon"/>
        limit #{startIndex},#{pageSize}
    </select>


    <select id="getTotalNum" parameterType="com.floor.shop.query.ProductQueryObj" resultType="int">
        SELECT COUNT(1) totalNum FROM product
        <include refid="queryCommon"/>
    </select>