package cn.dw.zh.dao;

import java.util.List;

import cn.dw.zh.model.Power;

public interface PowerDao {
   public void add(Power power);
   public void update(Power power);
   public void del(Integer id);
   public List<Power> query(Power power);
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.dw.zh.dao.PowerDao">
    <insert id="add" parameterType="cn.dw.zh.model.Power">
        <!-- insert into power(name,age) values('zs',22) -->
        insert into power
        <trim prefix="(" suffix=")" suffixOverrides=",">

            <if test="location != null and location !=''">

                location,
            </if>

            <if test="elec != null">

                elec,
            </if>

            <if test="etime != null ">

                etime,
            </if>
        </trim>

        values
        <trim prefix="(" suffix=")" suffixOverrides=",">

            <if test="location != null and location !=''">

                #{location},
            </if>

            <if test="elec != null">

                #{elec},
            </if>

            <if test="etime != null ">

                #{etime},
            </if>
        </trim>
    </insert>

    <update id="update" parameterType="cn.dw.zh.model.Power">

       update power <!-- location = '',elec ='' -->
       <set>

            <if test="location != null and location !=''">

                location= #{location},
            </if>

            <if test="elec != null">

                elec = #{elec},
            </if>

            <if test="etime != null ">

                etime = #{etime},
            </if>
       </set>
       where id = #{id}
    </update>


     <delete id="del" parameterType="int">

     delete from power where id = #{id}
     </delete>

     <select id="query" parameterType="cn.dw.zh.model.Power" resultType="cn.dw.zh.model.Power">
        select * from power <!-- where location = '' and elec = elec  and etime = '' where id = '' -->
         <where>
            <if test="location != null and location !=''">

                and location= #{location}
            </if>

            <if test="elec != null">

                and elec = #{elec}
            </if>

            <if test="etime != null ">

                and etime = #{etime}
            </if>
         </where>
     </select>

</mapper>