現在有一張訂單表t_stockorder,其擁有id、code、client_id、merchandise_id、merchandise_number、order_date、operator_id這些字段,其中client_id關聯t_client表中code字段,merchandise_id關聯t_merchandise表的code字段,operator_id關聯t_employee表的code字段。
現在要通過SQL語句將訂單表中t_stockorder的數據全部查詢出來,SQL語句如下所示:
select so.id, so.code, c.name cname, m.name mname,
so.merchandise_number,
so.order_date, e.name ename
from
inventory.t_stockorder so
inner join
inventory.t_client c on c.code = so.client_id
inner join
inventory.t_merchandise m on m.code = so.merchandise_id
inner join
inventory.t_employee e on e.code = so.operator_id
現在要在mapper映射文件中添加動態Sql語句,一般情況下映射文件中的resultMap元素中只可以有一個association,那如何添加多個association到resultMap中呢?正確代碼如下圖所示:
<resultMap id="StockorderMap" type="com.lwz.entity.Stockorder">
<id property="id" column="id" />
<result property="code" column="code" />
<result property="merchandiseNumber" column="merchandise_number" />
<result property="orderDate" column="order_date" />
<association property="client" javaType="Client" resultMap="ClientResultMap"></association>
<association property="merchandise" javaType="Merchandise" resultMap="MerchandiseResultMap"></association>
<association property="employee" javaType="Employee" resultMap="EmployeeResultMap"></association>
</resultMap>
<resultMap id="ClientResultMap" type="com.lwz.entity.Client">
<id property="code" column="code" />
<result property="name" column="cname" />
</resultMap>
<resultMap id="MerchandiseResultMap" type="com.lwz.entity.Merchandise">
<id property="code" column="code" />
<result property="name" column="mname" />
</resultMap>
<resultMap id="EmployeeResultMap" type="com.lwz.entity.Employee">
<id property="code" column="code" />
<result property="name" column="ename" />
</resultMap>
<!--通過實體作爲篩選條件查詢-->
<select id="queryAll" resultMap="StockorderMap">
select so.id, so.code, c.name cname, m.name mname,
so.merchandise_number,
so.order_date, e.name ename
from
inventory.t_stockorder so
inner join
inventory.t_client c on c.code = so.client_id
inner join
inventory.t_merchandise m on m.code = so.merchandise_id
inner join
inventory.t_employee e on e.code = so.operator_id
<where>
<if test="id != null">
and id = #{id}
</if>
<if test="code != null and code != ''">
and so.code = #{code}
</if>
<if test="client != null">
and client_id = #{client.code}
</if>
<if test="merchandise != null">
and merchandise_id = #{merchandise.code}
</if>
<if test="merchandiseNumber != null">
and merchandise_number = #{merchandiseNumber}
</if>
<if test="orderDate != null">
and order_date = #{orderDate}
</if>
<if test="employee != null">
and operator_id = #{employee.code}
</if>
</where>
</select>