PostgreSQL数据库中获取表主键名称 一.如下表示,要获取teacher表的主键信息: select pg_constraint.conname as pk_name,pg_attribute.attname as colname,pg_type.typname as typename from pg_constraint inner join pg_class on pg_constraint.conrelid = pg_class.oid inner join pg_attribute
It was only a matter of time, right? Due to my recent infatuation passionate love affair with PowerShell (whose download has been up and down on MSDN today...not sure why) I realized that I was missing something - the same behavior that I'd gotten ho
原文:https://www.binss.me/blog/the-context-manager-of-python-and-the-applications-in-tornado/ 上下文是什么? 在协程中,我将上下文理解为“操作执行时需要的一个特定的执行环境“.在该环境中,“上文”提供该操作需要的变量等信息,“下文“对操作执行返回的结果进行进一步的处理. 比如: def add(a, b): op = '+' result = yield cal(op, a, b) prin