mybatis中if判断把整数0识别为false(深坑)

1先看mybatis配置文件

<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测试方法

@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类型，order_settle_partner表里settle_status为0的有2条数据，为1的有一条数据，如下图：

4 测试结果根据settleStatus传入0，却返回3条记录，如下图：

5错误原因：

1. <if test="settleStatus != null and settleStatus != ''">中settleStatus为integer类型的，settleStatus=0的判断结果为false，mybatis把settleStatus作为了string来进行判断。

6解决办法：去掉settleStatus !=''的判断，改成下面的判断

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