問題：
Is there a command in PostgreSQL to select active connections to a given database? PostgreSQL 中是否有一個命令可以選擇到給定數據庫的活動連接？
psql states that I can't drop one of my databases because there are active connections to it , so I would like to see what the connections are (and from which machines) psql聲明我不能刪除我的數據庫之一，因爲有活動連接到它，所以我想看看連接是什麼（以及來自哪些機器）
解決方案：
參考一： https://stackoom.com/question/1r7JX參考二： How to list active connections on PostgreSQL?