java动态mybatis xml查询

Question

需要以下动态查询的帮助：

if country==null OR country != (spain || Peru)
select * from emp where country NOT IN (spain,Peru)
else
select * from emp where country=#{country}

我试过这样的方法，但没用：

<when test="country ==null" or country !='spain' or country != 'Peru'">
            AND country NOT IN ('spain','peru')
            </when>
            <otherwise>
            AND country=#{country}
 </otherwise>

即使国家=美国，也始终不产生

Answer 1

使用双引号来表示字符串

<when test='country == null or !country.equals("spain") or !country.equals("uk")'>
        AND country NOT IN ('spain','uk')
        </when>
        <otherwise>
        AND country=#{country}
 </otherwise>

Answer 2

<when test="country !='spain' and country != 'uk'">

错误的条件，预期的，而不是或

Answer 3

试试这个test="country == null or country != 'spain' or country != 'UK' "