目录

1.示例代码

2.说明

1.示例代码

<update id="updateNrPurchaseOrderDetailByGoodsBarcode">
    update nr_purchase_order_detail
    set stored_num =
    <foreach collection="barcodeList" item="item" index="index"
             separator=" " open="case goods_barcode" close="end">
        when #{item.barcode} then stored_num + #{item.receiveNum}
    </foreach>
    ,unstored_num =
    <foreach collection="barcodeList" item="item" index="index"
             separator=" " open="case goods_barcode" close="end">
        when #{item.barcode} then actual_goods_num - stored_num
    </foreach>
    where goods_barcode in
    <foreach collection="barcodeList" item="item" index="index" separator="," open="(" close=")">
        #{item.barcode}
    </foreach>
    and parent_id = #{id}
</update>

<!--caseWhen形式更新-->
<update id="testCaseWhen" parameterType="java.util.Map">
    UPDATE ${user}
    <set>
        <trim prefix="id= CASE id" suffix="END,">
            <foreach collection="list" item="param">
                <if test="param.id != null and id != ''">
                    WHEN #{param.id} THEN #{param.id}
                </if>
            </foreach>
        </trim>
        <trim prefix="username = CASE id" suffix="END,">
            <foreach collection="list" item="param">
                <if test="param.username != null and param.username != ''">
                    WHEN #{param.} THEN #{param.username}
                </if>
            </foreach>
        </trim>
        <trim prefix="password = CASE id" suffix="END,">
            <foreach collection="list" item="param">
                <if test="param.password != null and param.password != ''">
                    WHEN #{param.id} THEN #{param.password}
                </if>
            </foreach>
        </trim>
    </set>
    <where>
        id in
        <foreach collection="list" item="param" separator="," open="(" close=")">
            #{param.id}
        </foreach>
    </where>
</update>

2.说明

上述第一个示例中，按照条码进行批量更新，将所有的条码对应的入库数量和剩余数量进行更新。

第二个示例中，又使用了set标签和trim标签，感觉更为复杂。