1, The mysqldump command backs up data
MySQL provides a convenient tool mysqldump for exporting database data and files from the command line. We can export database contents directly from the command line.
#MySQL dump common
mysqldump -u root -p --databases Database 1 database 2 > xxx.sql
2, mysqldump common operation examples
1. Back ...
Posted on Sat, 20 Nov 2021 11:47:53 -0500 by lottos
Basic SELECT statement
1, SQL overview
1. SQL background
In 1974, IBM researchers published a paper "sequence: a structured English query language", which unveiled database technology. Up to now, this structured query language has not changed much. Compared with other languages, the half-life of SQL can be said to be very long. S ...
Posted on Sat, 20 Nov 2021 09:34:12 -0500 by Arrow
Recently, when learning Lin Ziyu's big data, I found that installing Hive for Hadoop requires using MySQL database to save Hive metadata, rather than using Hive's own derby to store metadata. In order to fill the gap in the big data column, consult the materials to complete this blog.
System version: Ubuntu 20.04
1, MySQL ins ...
Posted on Sat, 20 Nov 2021 03:50:43 -0500 by andybrooke
1, Introduction to master-slave replication
1.1 what is master-slave replication
Copy the binlog log of the master server to the slave server for execution to achieve the consistent state of the master-slave data, which is called master-slave replication. In a word, what the master database does is what the slave database does.
1.2 why s ...
Posted on Fri, 19 Nov 2021 18:28:24 -0500 by ravira
CentOS 7 Binary Installation MySQL 5.7
Host: CentOS Linux release 7.9.2009 (Core) Minimal Install
Install using the Linux - Generic TAR package
Mysql Compressed Pack Official Download Address: https://downloads.mysql.com/archives/community/
Select Version:5.7.31 Select Operating System:Linux - Generic Select OS Ve ...
Posted on Fri, 19 Nov 2021 14:06:24 -0500 by adamgeorge
Note: the following will use the emp table in the mysql database in the mysql database management system as an example
This content continues from the previous study notes: DQL statement 2 in SQL (learning note 3)
1, Grouping function
Grouping function is also called multi line processing function, and there are only 5 multi line proce ...
Posted on Fri, 19 Nov 2021 13:32:06 -0500 by nainil
This is the self-study notes of crazy God's mysql, which is only for reference, learning and continuous updating
The following is a video learning link: https://www.bilibili.com/video/BV1NJ411J79W
10. JDBC (key)
10.1. Database driver
Driver: sound card, graphics card, database Our program will deal with the database throug ...
Posted on Fri, 19 Nov 2021 07:26:42 -0500 by lucifer27
throw away a brick in order to get a gem
When and when are we talking about the "pool"? I remember the last time it was an IO stream, I created a buffer pool to speed up the read / write speed (actually reducing the number of IO operations)
So when will the connection pool be used???
Connection pooling is a technique for cre ...
Posted on Fri, 19 Nov 2021 07:15:50 -0500 by mgoerz
mysql database notes
DQL: query statement 1. Sort query 2. Aggregate function 3. Group query 4. Paging query
constraint Relationship between multiple tables normal form Backup and restore of database DQL: query statement Sort query
Syntax: order by clause
order by sort field 1, sort by 1, sort field 2, sort by 2 Sort by: ...
Posted on Fri, 19 Nov 2021 02:39:08 -0500 by thecard