MERGE优点: 在批量处理数据的时候,我可以用到merge一次完成数据处理. 示例代码一: MERGE INTO student AS t using ( AS age) s ON t.Age=s.age WHEN MATCHED THEN UPDATE SET t.Name=s.NAME WHEN NOT MATCHED THEN INSERT VALUES(s.NAME,s.age) WHEN NOT MATCHED BY SOURCE THEN DELETE; 实例一output还可以返
一个很简单的例子,用途是监听zookeeper中某个节点数据的变化,具体请参见代码中的注释 using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading; using System.Threading.Tasks; using ZooKeeperNet; namespace ZooKeeperDemo { /// <summary> ///
速查mysql数据大小 # 1.查看所有数据库大小 mysql> select concat(round(sum(DATA_LENGTH/1024/1024),2),'MB') as data from information_schema.TABLES; # 2.查看指定数据库大小 mysql> select concat(round(sum(DATA_LENGTH/1024/1024),2),'MB') as data from information_schema.TABLES wher