Category：MySql
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Knowledge database
1、 Knowledge database 1.1 why learn database Job demand Big data Era Forced demand: save data Database is the core of all software systems DBA 1.2. What is a database database （DB，DataBase） Concept: data warehouse,Software, installed on the operating system (window, Linux, MAC, etc.) Above Function: store and manage data DBMS (database management […]
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Four ways for MySQL to avoid repeatedly inserting data
The most common way is to set the primary key or unique index for the field. When inserting duplicate data, an error will be thrown and the program will terminate, but this will bring trouble to the subsequent processing. Therefore, special processing needs to be done for the insertion statement to avoid or ignore exceptions […]
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MySQL explain field meaning
Explain contains ID and select_ type、table、type、possible_ keys、key、key_ Len, ref, rows, extra field ID The number of the ID column is the serial number of the select. If there are several selections, there are several IDS, and the order of IDS increases in the order in which the select appears. select_type select_ Type indicates whether […]
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Sqlyog resource and activation method of MySQL desktop tool command line
If you don’t say much, go to resources first Developeppaer Download SQLyog Ultimate V13. 1.1 64bit Chinese registered installed version Open help after installation – change registration details Then the user fills in the registration key casually 60c1b896-7c22-4405-9f46-a6bce776ab36 Then you can use it. Fill in the server address you need to connect here, which is […]
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MySQL addition, deletion, modification and query (Basic + detailed explanation)
catalogue 💖1. CRUD 💖2. Create 2.1 single row data + full column insertion 2.2 multi row data + specified column insertion 💖3. Retrieve 3.1 full column query 3.2. Specify column query 3.3 the query field is an expression 3.4 alias 3.5 weight removal: distinct 3.6 sorting: order by 3.7 query criteria: where 3.8 paging query: […]
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MySQL small exercise (only suitable for beginners, non beginners are not allowed to enter)
Personal homepage:Personal home pageSeries column:Mysql database Ha ha, this is our teacher’s assignment. I wonder if I need to blog? Finally, I thought about it and sent it out. Although it’s very simple, it can be practiced for those friends who have just learned database.Because there is no answer, I don’t know whether it’s right […]
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[Python tutorial] nanny version teaches how to use pymysql module to connect mysql to realize addition, deletion, modification and query
Article catalogue preface Previous knowledge points Implementation steps （1） Installation of Library （2） MySQL create database （3） Pycharm connects to MySQL and creates tables （4） Pycharm connects Mysql to add, delete, modify and query epilogue preface MySQL is one of the most popular databases and the most popular open source relational database in the world. […]
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MySQL online DDL tool GH OST
I brief introduction GH OST is based on golang language. It is an open source DDL tool of GitHub. It is the abbreviation of GitHub’s online schema transformer / transformer / transformer / thing, which means GitHub’s online table definition converter. 1.1 principle Main implementation principles,firstBuild two tables, one_ GHO’s shadow table, GH OST will […]
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Summary of MySQL log related knowledge
The file used to store data in the database is called data file, and the log file is called log file. In addition, if you directly access the disk every time you read or write, the performance is very poor, so the database has cache, data buffer and log buffer. SQL execution order When we […]
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mysql8. 0.28 download and install detailed tutorials for win11
mysql8. 0.28 installation tutorial If you want to download the latest version, go to MySQL’s official website: download address:mysql Online disk download link version: 8.0.28 Baidu online diskExtraction code: xala Alibaba network disk 1. Enter the official website and click domnloads 2. Here we find the community version to download 3. Find MySQL community server […]
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MySQL advanced statement (I)
catalogue 1、 SQL advanced statement 1. Import file to database 2. select 3. distinct 4.where 5.and;or 6.in 7.between 8. Like wildcard 9. order by 10.group by 11.having 12. Alias 13. Connection query 14. Sub query 15.EXISTS 1、 SQL advanced statement 1. Import file to database #Import script into source plus file path mysql> source /backup/test.sql; […]
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Teach you how to build amazing blogs
Catalogue of series articles The first chapter teaches you how to build your own blog Article catalogue Catalogue of series articles preface 1、 Selection of website software 2、 Choice of website space 1. It is recommended to choose famous and large factories 2. Easy to use, rich and detailed documents 3. Be stable and have […]