SQL 用 in 大于 1000 问题解决

-- 今天生成环境数据突然多，系统异常 解决方案(必须用in 业务情况),也可以用其他函数解决 union all  或者 exists 等

1：截取list

public List<List<String>> trunListDate(List<String> list) {
    List<List<String>> listsgroup = new ArrayList<>();
    int n = list.size() / 999;
    for (int i = 0; i < n; i++) {
        listsgroup.add(list.subList(999 * i, list.size()));
    }
    if ((list.size() - n * 999) > 0) {
        listsgroup.add(list.subList(999 * n, list.size()));
    }
    return listsgroup;
}

2 ：将List<String> 划分为List<List<String>>

按指定大小，分隔集合，将集合按规定个数分为n个部分

private static List<List<String>> splitList(List<String> list, int len) {
if (list == null || list.size() == 0 || len < 1) {
return null;
}
List<List<String>> result = new ArrayList<List<String>>();
int size = list.size();
int count = (size + len - 1) / len;
for (int i = 0; i < count; i++) {
List<String> subList = list.subList(i * len, ((i + 1) * len > size ? size : len * (i + 1)));
result.add(subList);
}
return result;
}

3.

改为： 入参为List<List<String>>

WHERE name IS NOT NULL
<if test="userids!=null and userids.size()>0" >
and
<foreach collection="userids" item="userid" open="(" separator="or" close=")">
createby in
<foreach collection="userid" item="createby" open="(" separator="," close=")">
#{createby}
</foreach>
</foreach>
</if>

效果 where xxx and (createby in (1,2,3,4,5 .... ,999) or createby in(1000,1001,....,1040))