第一种方法：in 条件为拼接好的字符串

直接传入拼接好的where in 条件，如（’111’,’222’,’333’)则需要使用${idlist}传参，即绝对引用，而不能使用#, 如果使用#传参会被mybatis当成字符串再添加一层’’引号，导致错误。
优点：简单方便，高效，缺点：不能防止SQL注入
list转换为Sql条件字符串代码如下：

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StringBuilder sqlString = new StringBuilder();

for (int i = 0; i < exhCollectForm.getSelectedCloId().size(); i++) {
    if (i > 0) {
        sqlString.append(",");
    }
    sqlString.append("'").append(exhCollectForm.getSelectedCloId().get(i)).append("'");
}
String result = sqlString.toString();

第二种方法：in 条件为List对象

in条件直接传入List对象，让mybatis再去拼接生成in条件，这个很麻烦,但是可以防止SQL注入

第三种方法：in 条件为String[] 数组

in条件直接传入[]数组对象，让mybatis再去拼接生成in条件，这个很麻烦,但是可以防止SQL注入
Service:

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int deleteMenuByIdList(String idlist,int delcount,int lastsort);
int deleteMenuByIdList(List<String> idlist, int delcount,int lastsort);
int deleteMenuByIdList(String[] idlist, int delcount,int lastsort);

Dao:

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//用这种写法方便，idlist直接拼接好，xml中用 in ${idlist}接受参数
int deleteMenuByIdList(@Param("idlist")String idlist, @Param("delcount")int delcount, @Param("lastsort")int lastsort);
//用这种写法直接传List对象，xml中再写循环拼接，麻烦
int deleteMenuByIdList2(@Param("idlist")List<String> idlist, @Param("delcount")int delcount, @Param("lastsort")int lastsort);
//用这种写法直接传String[]数组，xml中再写循环拼接，麻烦
int deleteMenuByIdList3(@Param("idlist")String[] idlist, @Param("delcount")int delcount, @Param("lastsort")int lastsort);

mappper.xml

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1，
    <delete id="deleteMenuByIdList" >
      delete from s_menu  where menu_id in ${idlist};
      update s_menu set sort=sort-#{delcount} where sort >= #{lastsort} and menu_id not in ${idlist};
    </delete>
 
2，
    <delete id="deleteMenuByIdList2" >
        delete from s_menu where menu_id in
        <foreach collection="idlist" item="menu_id" separator="," open="(" close=")">
            #{menu_id}
        </foreach>
      ;update s_menu set sort=sort-#{delcount} where sort >= #{lastsort} and menu_id not in
       <foreach collection="idlist" item="menu_id" separator="," open="(" close=")">
           #{menu_id}
       </foreach>;
    </delete>
 
3，
    <delete id="deleteMenuByIdList3" >
        delete from s_menu where menu_id in
        <foreach collection="idlist" item="menu_id" separator="," open="(" close=")">
            #{menu_id}
        </foreach>
        ;update s_menu set sort=sort-#{delcount} where sort >= #{lastsort} and menu_id not in
        <foreach collection="idlist" item="menu_id" separator="," open="(" close=")">
            #{menu_id}
        </foreach>;
    </delete>

原文链接：https://blog.csdn.net/wh445306/article/details/111056331