解决MySQL读写分离导致insert后select不到数据的问题

// 先录入
this.insert(obj); 
// 再查询
Object res = this.selectById(obj.getId());
res: null;

INSERT INTO table(field1, field2, fieldn) 
SELECT 'field1', 'field2', 'fieldn' 
FROM DUAL
WHERE NOT EXISTS(SELECT field FROM table WHERE field = ?)

INSERT INTO a (order_id, operator, oper_date, memo) 
SELECT '3', 'onion3', '2017-11-28', '测试3' 
from DUAL 
where not exists(select order_id from a where operator='onion3' and memo = '测试3');