在开发中，经常会遇到这种情况，在程序集A.dll中需要反射程序集B.dll中的类型。如果使用稍有不慎，就会产生运行时错误。
反射的优缺点： 优点：提高了程序的灵活性和扩展性，降低耦合度 缺点：由于反射多了一道程序，性能上相较于直接代码要慢
SQL Server 将某些系统事件和用户定义事件记录到 SQL Server 错误日志和 Microsoft Windows 应用程序日志中。 这两种日志都会自动给所有记录事件加上时间戳。 使用 SQL Server 错误日志中的信息可以解决SQL Server的相关问题。
application/x-font-woff
System.NullReferenceException:“未将对象引用设置到对象的实例。
Lost connection to MySQL server…
[ERROR] InnoDB: Expected to open 3 undo tablespaces but was able to find only 0 undo tablespaces. Set the innodb_undo_tablespaces parameter to the correct value and retry. Suggested value is 0
ERROR 1418 (HY000): This function has none of DETERMINISTIC, NO SQL, or READS SQL DATA in its declaration and binary logging is enabled (you *might* want to use the less safe log_bin_trust_function_creators variable)
Error Code: 1175. You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column.
Error 1390 (HY000): Prepared statement contains too many placeholders
