原来代码：
<select id="findSpecialOffer" resultType="com.lizard.back.model.SpecialOffer" parameterType="java.lang.String">
SELECT
taso.id,
taso.product_id as productId ,
taso.table_name as tableName,
taso.start_time_special_off as startTimeSpecialOff,
taso.end_time_special as endTimeSpecial,
taso.create_time as createTime,
taso.operator,
tau.mobile as mobile,
taso.is_effective as isEffective,
taso.type
FROM
`t_admin_special_offer` taso
INNER JOIN t_admin_user tau ON tau.uid = taso.operator
<if test="isEffective!=null">
where taso.is_effective = #{isEffective,jdbcType=VARCHAR}
</if>
</select>
解决方法： 不管你的参数是什么，都要改成"_parameter"
<select id="findSpecialOffer" resultType="com.lizard.back.model.SpecialOffer" parameterType="java.lang.String">
SELECT
taso.id,
taso.product_id as productId ,
taso.table_name as tableName,
taso.start_time_special_off as startTimeSpecialOff,
taso.end_time_special as endTimeSpecial,
taso.create_time as createTime,
taso.operator,
tau.mobile as mobile,
taso.is_effective as isEffective,
taso.type
FROM
`t_admin_special_offer` taso
INNER JOIN t_admin_user tau ON tau.uid = taso.operator
<if test="_parameter !=null and _parameter !=‘‘">
where taso.is_effective = #{isEffective,jdbcType=VARCHAR}
</if>
</select>
（mybatis）There is no getter for property named 'isEffective' in 'class java.lang.String
原文：https://www.cnblogs.com/EveningWind/p/10025968.html