记一次mybatis的坑

<select id="getProjectIdsByCompanyId" parameterType="java.lang.Long" resultType="long">

  select distinct projectId from oil_credit_company_project where 1=1

<if test="companyId!=null and companyId !=0L">

          AND companyId = #{companyId}

</if>

</select>

基本类型参数  是没法判断空值的。