PL/pgSQL 存储过程中,不支持直接使用 SELECT 查询返回结果,只能用 "SELECT
INTO" (https://link.segmentfault.com/?enc=JQEh7ThaXvdHVX%2F413ABbQ%3D%3D.HIFpX8h%2FZLiG30M%2FY0jtSmr2dAGdDNJl78zhNhoXxenSd82NOlW9KuZrhiGbs4dXzPwABkYhJ%2Bi9QN8oGWVSvA%3D%3D)
保存结果到变量;
可以看下 "PostgreSQL PL/pgSQL
教程" (https://link.segmentfault.com/?enc=pb6pQckvVY1XOhuVe1xqVQ%3D%3D.e6hY1%2BEwgpg64gaN6NS4hh2rQpGVX6onUwe9O5oMwyL%2BSfoRUOLqt9Xz%2Fvp0Qn%2BMH3mSpmntOkqpwfceT0fcSw%3D%3D),参考样例学习一下。