说明：统计psyt类型的rw数量，psyt存储的格式（11，22，33，44）
原理：
substring_index(a.usualusecurrentstatusid, ',', n) ----截取第n个逗号前的数字
substring_index(a.usualusecurrentstatusid, ',', -1) ----截取最后一个逗号后边的值
substring_index(substring_index(a.usualusecurrentstatusid, ',', b.id + 1), ',', - 1)
根据 后边的legth减法计算有几个数值，根据此数值循环拿出（11，22，33，44）最里层的截取是获得前面的数据，外层的截取是获得最后的数据
例：有四个值，因为on 条件是<4;
第一步 substring_index(a.usualusecurrentstatusid, ',', 1), ',', - 1) ------》11---》11
第二步substring_index(a.usualusecurrentstatusid, ',', 2), ',', - 1) ------》11，22---》22
第三步substring_index(a.usualusecurrentstatusid, ',', 3), ',', - 1) ------》11，22，33---》33
第四步substring_index(a.usualusecurrentstatusid, ',', 4), ',', - 1) ------》11，22，33，44---》44
最后根据group by 统计数量
select count(aa.bh) gs,sd.id rfxzId,sd.item_text rfxz,sum(aa.ryarea) z_ryarea,sum(aa.rfarea) z_rfarea from (
SELECT a.bh,a.ryarea,a.rfarea
, substring_index(
substring_index(a.usualusecurrentstatusid, ',', b.id + 1), ',', - 1) AS usualusecurrentstatusid
FROM rf_projectinfo a
join sys_dict_item sdi on sdi.id=a.streetid and a.del=0
INNER JOIN rf_split_helper b
ON b.id < (length(a.usualusecurrentstatusid) - length(REPLACE(a.usualusecurrentstatusid, ',', ''))
+ 1) where a.del=0) aa left join sys_dict_item sd on sd.id=aa.usualusecurrentstatusid
group by aa.usualusecurrentstatusid ORDER BY gs desc
需要增加辅助表：
create table rf_split_helper
(
id int(30) null
);
INSERT INTO rf_split_helper (id) VALUES (0);
INSERT INTO rf_split_helper (id) VALUES (1);
INSERT INTO rf_split_helper (id) VALUES (2);
INSERT INTO rf_split_helper (id) VALUES (3);
INSERT INTO rf_split_helper (id) VALUES (4);
INSERT INTO rf_split_helper (id) VALUES (5);
INSERT INTO rf_split_helper (id) VALUES (6);
INSERT INTO rf_split_helper (id) VALUES (7);
INSERT INTO rf_split_helper (id) VALUES (8);
INSERT INTO rf_split_helper (id) VALUES (9);
INSERT INTO rf_split_helper (id) VALUES (10);
INSERT INTO rf_split_helper (id) VALUES (11);
INSERT INTO rf_split_helper (id) VALUES (12);
INSERT INTO rf_split_helper (id) VALUES (13);
INSERT INTO rf_split_helper (id) VALUES (14);
INSERT INTO rf_split_helper (id) VALUES (15);
INSERT INTO rf_split_helper (id) VALUES (16);
INSERT INTO rf_split_helper (id) VALUES (17);
INSERT INTO rf_split_helper (id) VALUES (18);
INSERT INTO rf_split_helper (id) VALUES (19);
INSERT INTO rf_split_helper (id) VALUES (20);
INSERT INTO rf_split_helper (id) VALUES (21);
INSERT INTO rf_split_helper (id) VALUES (22);
INSERT INTO rf_split_helper (id) VALUES (23);
INSERT INTO rf_split_helper (id) VALUES (24);
INSERT INTO rf_split_helper (id) VALUES (25);
INSERT INTO rf_split_helper (id) VALUES (26);
INSERT INTO rf_split_helper (id) VALUES (27);
INSERT INTO rf_split_helper (id) VALUES (28);
INSERT INTO rf_split_helper (id) VALUES (29);
INSERT INTO rf_split_helper (id) VALUES (30);
