UNPIVOT reverse perspective and dynamic reverse perspective stored procedure

I practiced PIVOT perspective the other day and realized the saving process of dynamic perspective< Dynamic PivotTable>https://www.cnblogs.com/insus/p/10888277.html Today, I will practice the function of MS SQL Server reverse perspective. First, prepare some data that can be inverted perspective:   IF OBJECT_ID('tempdb.dbo.#Part_ ...

Posted on Thu, 07 Nov 2019 08:13:37 -0800 by Petrushka

Failure scenario of MySQL index

In today's work, I encountered the scenario of index failure. Let's record it here. Because the working sql is not easy to paste, create a test table offline for replication. I. preparation of experimental data CREATE TABLE `test_order` ( `id` int(11) NOT NULL AUTO_INCREMENT, `order_name` varc ...

Posted on Sat, 26 Oct 2019 10:02:51 -0700 by jjfletch

Python Road [Article 24]: Database Index

Database Index Introduction to Index Index, also known as "key" in mysql, is a data structure used by storage engines to quickly find records. Indexing is critical to good performance, especially when the amount of data in tables is increasing, the impact of indexing on performance becomes more and more important.   Index optimiza ...

Posted on Sat, 05 Oct 2019 03:17:31 -0700 by proctk

Mysql Stored Procedures

stored procedure know In some programming languages, such as pascal, there is a concept called "process" and "function", such as sub. Java, Python, PHP in VB, no process, only function. Procedure: Several statements are encapsulated and executed when invoked. Function: A process with a return value (ps: Python function is bo ...

Posted on Fri, 04 Oct 2019 14:11:12 -0700 by gladius

oracle Basic Knowledge Accumulation - Create Packages and Packages bodies

Scene: Basic Knowledge Query Motivation: Pure basic knowledge is accumulated to facilitate follow-up inquiries. In many occasions, people in charge are talking about going to IOE. Therefore, inevitably, the use of occasions will be more or less reduced, so according to the customary thinking record. ...

Posted on Thu, 03 Oct 2019 16:29:49 -0700 by bough

Mysql stored procedures traverse pits where values cannot be obtained

Undoubtedly, this must be a sad story. I have a requirement here. I need to migrate and backup some records and log tables. Under the current conditions, we do not use MaxCompute for backup, nor do we handle it gracefully through master-slave databas ...

Posted on Wed, 04 Sep 2019 20:39:02 -0700 by nofxsapunk

MySQL (Learning Notes) - Database Views, Triggers and Stored Procedures

_Database View, Triggers and Stored Procedures _1. What is a view? Definition: Views are virtual tables derived from one or more tables in a database and are not in memory. Grammar: create view View Name //(Create a view) as select Fi ...

Posted on Fri, 23 Aug 2019 05:54:07 -0700 by roopali

MySQL Database Advanced-Stored Procedures

Links to the original text: https://blog.51cto.com/9291927/2094915 Advanced MySQL Database (4) - Stored Procedures This article is reproduced from: https://blog.51cto.com/9291927/2094915 Introduction to Stored Procedu ...

Posted on Fri, 16 Aug 2019 06:35:31 -0700 by duankr

MySql || Quickly create 100w records

Normally, each developer will discuss the optimization of sql when there is a large amount of data.But not everyone has 100w of data to use for actual combat, so today we'll start by simulating a table of 100w of data. Creation principle In fact, there are many ways to create, fast and slow.This blog is certainly not the fastest one to writ ...

Posted on Sat, 10 Aug 2019 21:42:21 -0700 by Rupo

Oracle Learning Notes 4: pl/sql

1. What is pl/sql? sql: Structured Query Language pl/sql: (Procedure Language & Structured Query Language) is an extension of SQL language and stored procedure language. It can implement simple logic programming like Java language. 2. Advantages of pl/sql? From bloggers https://www.cnblogs.com/huyong/archive/2011/05/16/2047329.html See ...

Posted on Sun, 21 Jul 2019 20:41:56 -0700 by EGNJohn