Data Types and Special Types - C#

Reference address: https://blog.csdn.net/qiaoquan3/article/details/51380992 set: Pure Data set 2. Linear structure: one-to-one, array 3. Tree structure: one-to-many, menu/folder/category/attribute control/expression directory tree 4. Graphic/reticular structure: many-to-many, map application is more, and website application is less.   Lin ...

Posted on Sat, 21 Sep 2019 06:44:56 -0400 by c_coder

How to Delete Windows Authenticated Users Correctly by SQL Server

In the SQL Server database, sometimes some Windows-certified accounts (domain accounts) will be established. For example, our company is used to granting NT account rights to developers and Support colleagues. If there is a turnover or change of responsibility, how to delete these Windows-certified accounts correctly? This article is to explore ...

Posted on Sat, 21 Sep 2019 06:43:45 -0400 by deezzer

Introduction to Druid (Spring Boot + Mybatis + Druid Data Source [Customized by Yourself]

Introduction to Druid Druid is a very good database connection pool. In terms of function, performance and extensibility, it surpasses other database connection pools, including DBCP, C3P0, BoneCP, Proxool and JBoss Data Source. Druid has deployed more than 600 applications in Alibaba, after more than a year of rigorous deployment of large-scal ...

Posted on Sat, 21 Sep 2019 06:04:53 -0400 by jaronblake

Flask Learning Tour - or Database (sqlacodegen + SQL Alchemy)

I. Write in front In fact, I've written a blog about using database in Flask before, but that blog mainly records some problems I encountered when using Flask + MySQL 8.0 (if not MySQL 8.0, I don't think there will be so many problems!). Then this article can be counted as a learning note. It is also about database operation in Flask. It feels ...

Posted on Sat, 21 Sep 2019 02:40:14 -0400 by jammer

You're not going to be using these eight wrong SQL scripts, are you?

1. LIMIT statement Paging queries are one of the most common scenarios, but they are also often the most problematic. For example, for the following simple statements, DBA s generally think of a way to add a composite index to the type, name, create_time fields. In this way, conditional sorting can effectively use the index, and the performa ...

Posted on Fri, 20 Sep 2019 09:18:56 -0400 by Aeiri

Personal Evaluation and Selection of Payment Agents - Repetition Rate, Availability, Response Time, Stability, Price (for Reference only)

Because of the company's business requirements, the watermelon agent has not met the demand and is ready to replace the new agent IP pool, so the investigation and test of the various payment agents on the market (the low availability of free agents is not considered), functional constraints and price conditions, etc., in order to select the ag ...

Posted on Fri, 20 Sep 2019 08:42:28 -0400 by GingerApple

Connecting databases with Go

brief introduction Install gorm Start the database Initialize database connection Connect to the database at server startup summary The current part of the code brief introduction There are many ways to connect databases in Go. Here we choose to use ORM.There is no need to write native SQL statements. There are also many ORM libraries for Go, ...

Posted on Fri, 20 Sep 2019 07:13:21 -0400 by phpyoungdeveloper

Mybatis Foundation - Introduction

Mybatis Introduction and Environment Construction I. The Concept of Data Persistence Data persistence is the general term for transforming the data model in memory into the storage model and the storage model into the data model in memory. Mybatis Framework and ORM 1. Introduction to Mybatis Fr ...

Posted on Fri, 20 Sep 2019 06:59:16 -0400 by jimthunderbird

Redis|Sentinel High Availability Architecture

Preface Redis-Sentinel is Redis's official recommended high availability (HA) solution. When Redis is used as Master-slave's high availability solution, if the master is down, Redis itself (including many of its clients) does not automatically switch between master and backup, and Redis-sentinel itself is an independent running process, it can ...

Posted on Fri, 20 Sep 2019 06:29:09 -0400 by Lillefix

The Execution Order of MySQL Logical Query Statements

Definition order of keywords in a SELECT statement SELECT DISTINCT <select_list> FROM <left_table> <join_type> JOIN <right_table> ON <join_condition> WHERE <where_condition> GROUP BY <group_by_list> HAVING <having_condition> ORDER BY <order_by_condition> LIMIT <limit_number> Execution ...

Posted on Fri, 20 Sep 2019 04:47:56 -0400 by gp177