安装Vue中出现的问题
npm WARN deprecated har-validator5.1.5: this library is no longer supported npm WARN deprecated uuid3.4.0: Please upgrade to version 7 or higher. Older versions may use Math.random() in certain circumstances, which is known t o be pr…
1、问题
mysql中在设置主键(id)的默认值时,有一下两种情况:
当 id 为 int 类型时,可以直接在创建表时设置id为 id primary key auto_increase,即默认 id 为主键自增长。当 id 为 varchar 类型时ÿ…
性能分析工具
参照链接
long_query_time :默认10秒 SHOW VARIABLES LIKE %long_query_time%; ,设置set [global] long_query_time 1;slow_query_log: 查看慢查询日志SHOW VARIABLES LIKE %slow_query_log%;设置开启SET GLOBAL slow_query_logON;slow_…
缓冲流
import java.io.*;
import java.util.HashMap;/*** Create by xiye on 2019/12/5 11:40*/
public class Demo1_缓冲流 {/** BufferedInputStream与FileInputStream用法差不多,区别在于效率* BufferedInputStream有缓存(8192)&#…