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Summary of several methods for removing duplicate data in SQL (window function for data deduplication)
catalogueMethod 1: distinctMethod 2: groupbyMethod 3: Window functionWhen using SQL to extract and analyze data, we often encounter scenarios where data is duplicated, requiring us to perform data deduplication and subsequent analysis.Taking the sales report of a certain e-commerce company as an example, we commonly use distinct or group by statements to deduplicate data...
Database Operation Tutorial 2023-05-12 12:13:26 -
Steps to connect to a SQL Server database through Linux installation of ODBC
catalogue1. Download the ODBC installation package2...
Database Operation Tutorial 2023-05-12 12:13:06 -
SQL Server 2022 AlwaysOn New Features including Availability Group Details
catalogueHow to create an availability group?How to use including availability groups?3. Metadata synchronization verification3...
Database Operation Tutorial 2023-05-12 12:12:54 -
How to Convert Horizontal and Vertical Tables in SQL
catalogue1 Overview of Horizontal Tables2 Overview of the vertical table3 The code for converting a vertical table to a horizontal table is as follows and the view is displayed4 The code for converting horizontal table to vertical table is as follows and the view is displayed5 Advantages and disadvantages of horizontal and vertical tables6 Summary1 Overview of Horizontal TablesHorizontal table is a common way to create tables. For example, the table structure is primary key, field 1, field 2, and field 3…...
Database Operation Tutorial 2023-05-12 12:12:25 -
How to use Pycharm to connect to SQL Server (detailed tutorial)
SQL Sever1433 pycharmpycharmSQL SeverTipSQL Sever: ------------------------------ LAPTOP-40O6HVDS ------------------------------ : (provider: Shared Memory Provider, error: 0 - ) (Microsoft SQL Server: 233) SQL Sever SQL Sever Window create database soft2104soft2104soft2104pycharmuse master --drop database soft2104 -- yunmengzepycharmSQL Sever 123456123456pycharm db_ower SQL Sever SQL Sever: ------------------------------ LAPTOP-40O6HVDS ------------------------------ : (provider: Shared Memory Provider, error: 0 - ) (Microsoft SQL Server: 233) 1433 1433 1433winRcmdtelnet localhost 1433'telnet' winRcontrol Windows Telnet1winRcmdtelnet localhost 1433localhost....
Database Operation Tutorial 2023-05-12 12:12:22 -
Row_ Summary of the usage of the number() function
Row_ The number() function is a type of SQLSERVER system function that assigns a continuous integer to each row in the partition of the result set. Simply put, it is to generate a unique table with the sequence number starting from the first row of each partition...
Database Operation Tutorial 2023-05-12 12:12:05 -
SQL Server judges whether there is summary for database, table, column, view, stored procedure and function
catalogue1 Introduction Overview2 Database related judgments2.1...
Database Operation Tutorial 2023-05-12 12:11:57 -
Detailed Solution to SQL Server Installation Failure in Win11
catalogueDelete SQLServer related registryterms of settlement:summaryWin+R opens and runs the input services.msc to view all services and stop all services related to SqlServer, as follows:Open the control panel - uninstall all related software of SQL server;Delete SQLServer related registry1...
Database Operation Tutorial 2023-05-12 12:11:49 -
Detailed explanation of SQL Server's memory management architecture
WindowsSQL Server 2.12...
Database Operation Tutorial 2023-05-12 12:11:27 -
SQL Detailed explanation of server's row level security
catalogue1 Preface2 Description3 Permissions4 Security note: Side channel attack5 Cross functional compatibility6 Example1 PrefaceRow level security allows you to control access to rows in database tables using group membership or execution context.Row level security (RLS) simplifies security design and coding in applications...
Database Operation Tutorial 2023-05-12 12:11:21 -
The issue of SQL database connection timeout expired
catalogueSQL database connection timeout has expiredproblemresolventSummary of database access timeout configuration1. Background2...
Database Operation Tutorial 2023-05-12 12:10:55 -
Zhihu's "515 Employee Day" is about to start, focusing on the work and life of new employees
On May 12th, it was announced that Zhihu will launch the "515 Employee Day" series of activities from May 15th to May 31st. It is understood that China's employed population is giving birth to a group of "new employees" who have received higher education, have professional experience and skills, and are mainly engaged in advanced manufacturing and the tertiary industry...
internet 2023-05-12 12:09:29