1. Query every s in fruits table_ All f corresponding to ID_ Name value
#Compact in groups
mysql> select s_id,group_concat(f_name) as name from fruits group by s_id having count(f_name) > 1;
2. Same statistics s_ What are the rows of ID values?
mysql> select s_id,count(*) as total from fruits group by s_id with rollup;
Note: the role ...
Posted by puritania on Mon, 18 May 2020 15:05:43 +0200
Author: Yang Taotao
Senior database expert, specializing in MySQL for more than ten years. Good at mysql, PostgreSQL, MongoDB and other open-source database related backup and recovery, SQL tuning, monitoring operation and maintenance, high availability architecture design, etc. At present, he is working in aikesheng, providing MySQL related ...
Posted by trent2800 on Mon, 18 May 2020 11:20:05 +0200
It's been a month since I joined the new company, I've finished the work at hand, and the last few days I finally have time to research the code for my old project.During the process of researching the code, I found that Spring Aop was used in the project to separate the database from reading and writing, and to learn in my own way (I d ...
Posted by BraniffNET on Tue, 12 May 2020 18:48:39 +0200
yum install -y httpd
systemctl start httpd
Set apache to power on automatically
systemctl enable httpd
Access public network address to check whether apache is normal
Install MySQL database
wget -i http://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm
yum -y install mysql57-community-release-el7-10 ...
Posted by pedroteixeira07 on Mon, 11 May 2020 19:01:44 +0200
Meaning: Understand as a virtual table and use it like a regular table A new feature of MySQL version 5.1 is data generated dynamically from tables For example: a comparison between a dance class and an ordinary class
Differences between views and tables:
Create Grammar Keyword
Occupy physical space
Posted by coolbeansdude51 on Sun, 10 May 2020 09:10:57 +0200
php5 and php7 can be installed in an apache server at the same time, but only one of them can run. The other needs to comment out the corresponding LoadModule in the apache configuration file
1. Download and install
[root@dl-001 src]# wget http://cn2.php.net/distributions/php-7.1.6.tar.gz
[root@dl-001 s ...
Posted by cdinca on Tue, 05 May 2020 20:06:12 +0200
OS: CentOS release 6.9
CPU: 4 cores
1. Experiment host clone
Refer to "CentOS6 experimental machine template building and deployment"
Clone an experimental machine, adjust the memory to 2G and the CPU to 4 cores, and further configure the host na ...
Recently, we are trying to use a log system, graylog, to collect the slow query log of mysql for subsequent analysis, monitoring and alarm. The test steps have been completed and the logs have been collected successfully. During the test, you need to brush some slow query logs. In order to brush more logs and not have a greater impact o ...
Posted by murp32 on Mon, 04 May 2020 13:43:41 +0200
1, Start SSL on installation
[root@linux-node local]# /usr/local/mysql5.7/bin/mysqld --initialize --basedir=/usr/local/mysql5.7 --datadir=/usr/local/mysql5.7/data/ --user=mysql
[root@linux-node local]# /usr/local/mysql5.7/bin/mysql_ssl_rsa_setup
After running this command, the following pem files will be generated in the data directory by ...
Posted by matty on Mon, 04 May 2020 06:00:33 +0200