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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 ...

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 ...

<dependency> <groupId>com.github.pagehelper</groupId> <artifactId>pagehelper</artifactId> <version>5.1.8</version> </dependency> <dependency> <groupId>com.github.pagehelper</groupId> <artifactId ...

Preface 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 ...

Install apache yum install -y httpd Start apache 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 ...

view 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: Name Create Grammar Keyword Use Occupy physical space view ...

Explain 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 ...

Environment related: OS: CentOS release 6.9 IP: 192.168.1.10 CPU: 4 cores MEM: 2G DISK: 50G 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 ...

Preface 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 ...

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 ...