1先看mybatis配置檔案

<select id="listByParam"   resultMap="orderSettlePartnerResultMap" parameterType="com.jd.ept.settlement.domain.settle.OrderSettlePartner">
SELECT
    <include refid="all_table_column"/>
FROM
    order_settle_partner
    where 1=1
    <if test="settleStatus != null and settleStatus !=''"
 
>
AND settle_status = #{settleStatus}
    </if>
</select>

2再看Java測試方法

@Test
public void testByParam() {
    OrderSettlePartner orderSettlePartner=new OrderSettlePartner();
orderSettlePartner.setSettleStatus(0);
orderSettlePartner.setPartnerId(1);
List<OrderSettlePartner>  orderSettlePartnerList = orderSettlePartnerMapper
 
.listByParam(orderSettlePartner);
System.out.println(orderSettlePartnerList.size());
}

3 settleStatus是Integer型別，order_settle_partner表裡settle_status為0的有2條資料，為1的有一條資料，如下圖：

4 測試結果根據settleStatus傳入0，卻返回3條記錄，如下圖：

5錯誤原因：

1. <if test="settleStatus != null and settleStatus != ''">中settleStatus為integer型別的，settleStatus
   =0的判斷結果為false，mybatis把settleStatus作為了string來進行判斷。

6解決辦法：去掉settleStatus !=''的判斷，改成下面的判斷

<if test="settleStatus != null">
AND settle_status = #{settleStatus}
</if>