Tag:Record

  • MSSQL · take a record according to the maximum value of multiple fields and grouping according to a field

    Time:2021-7-29

    Reading time |1.14 minutes word count |1825.6 characters primary coverage |1. Introduction & background “MSSQL · take a record according to the maximum value of multiple fields and grouping according to a field” Author | SCscHero Writing time | 2021/7/12 PM12:0 Article type |Series Degree of completion |Completed motto Every great cause has a trivial […]

  • Meaning and difference between MySQL row lock and table lock

    Time:2021-7-29

    It is impossible that every day is a good day. When there are bad days, the good days will shine. 1、 Foreword The meaning difference between row lock and table lock should appear frequently in the interview. We should have a systematic understanding of the lock in MySQL. We need to consult the data in […]

  • Nginx 499 questions

    Time:2021-7-28

    scene An interface exception is found in the project. When viewing the nginx log, it is 499 error, request_ Time is about 0.2S. Google later learned that the 499 error of nginx was caused by the user actively disconnecting, even if the interface was not very slow. How to simulate 499 curl -m 0.01 “http://192.168.0.1/common/getDepart” […]

  • MSSQL · query and sort the records of all tables in a database

    Time:2021-7-28

    Reading time |0.27 minutes word count |444 characters primary coverage |1. Introduction & background “MSSQL · query and sort the records of all tables in a database” Author | SCscHero Writing time | 2021/7/13 PM10:0 Article type |Series Degree of completion |Completed motto Every great cause has a trivial beginning. 1、 Introduction & background    Completion: […]

  • Go and mongodb

    Time:2021-7-28

    Go does not have the concept of class, and the binding of variables is implemented by structs in the form of key value pairs.This is very friendly to mongodb and JSON, which are also stored as key value pairs. Therefore, in go, the ORM based on mongodb is not very dependent. It can be operated […]

  • The cache design is good, and the service will not fail

    Time:2021-7-27

    This article is modified from the live broadcast content of go zero in the fourth issue of “go open source theory”. The video content is long and divided into two parts. The content of this article has been deleted and reconstructed. Hello, I’m glad to come to “go open source theory” to share with you […]

  • Type of MySQL lock

    Time:2021-7-27

    Lock based attribute classification: shared lock and exclusive lock.Lock based granularity classification: row level lock (InnoDB), table level lock (InnoDB, MyISAM), page level lock (BDB engine), record lock and inter lockGap lock, temporary key lock.Lock based state classification: intentional shared lock and intentional exclusive lock. Share lock Shared lock, also known as read lock, is […]

  • Learn a Linux command every day (63): route

    Time:2021-7-26

    Recommended reading:Learn a Linux command every day (62): Ping Command introduction The route command is used to display and set the routing table (static routing table) of the Linux system. The route command is used to display and set the network routing table in the Linux kernel. The routes set by the route command are […]

  • Mongodb backup and restore command

    Time:2021-7-26

    backups mongodump –archive=gt_ut.archive –db gt_ut 2018-03-22T18:11:33.555+0800 writing gt_ut.gt_counting_data to archive ‘gt_ut.archive’ 2018-03-22T18:11:33.558+0800 done dumping gt_ut.gt_counting_data (2 documents) Backup to file namedgt_ut.archiveFile Attempt to repeat the backup The first backup file is overwritten mongodump –archive=gt_ut.archive –db gt_ut 2018-03-22T18:11:59.565+0800 writing gt_ut.gt_counting_data to archive ‘gt_ut.archive’ 2018-03-22T18:11:59.567+0800 done dumping gt_ut.gt_counting_data (2 documents) Restore now Execute after deleting a record […]

  • Laravel admin Association query

    Time:2021-7-25

    Original address:https://blog.csdn.net/yang101… rights_ exchange_ The log table is an equity exchange record associated with the user ID (user_ ID), you need to query the user redemption record according to the user’s mobile phone number. The expected final SQL is as follows: SELECT * FROM `rights_exchange_log` LEFT JOIN `fk_member` ON `fk_member`.`id` = `rights_exchange_log`.`member_id` WHERE `fk_member`.`tel` = […]

  • Mongode revisits the road (1)

    Time:2021-7-23

    Starting mongodb with Windows Service //Create directory d: data/ Conf — > configuration file directory Mongod.conf — > configuration file DB — > database directory Log file directory Mongodb. Log — > logging file First, open the DOS window as an administrator //Execute the following command C:\WINDOWS\system32>mongod –dbpath “d:\data\db” –logpath “d:\data\log\mongodb.log” –serviceName “mongodb” –serviceDisplayName “mongodb” […]

  • Git reflog rolls back local code

    Time:2021-7-22

    background Programmer a makes three local commit ‘Demo1’, ‘demo2’ and ‘demo3’ Programmer a accidentally rolls back git reset — hard ‘commit1’, and rolls back to the first commit Programmer a modifies the file and makes a commit, ‘demo4’ Q: how to retrieve the two reset commit and merge the latest commit ‘demo4’ Using git log, […]