Where is MySQL / MariaDB storage location by default on CentOS 7? No special configuration to the MariaDB from official repository of CentOS. On CentOS 7 Linux it is usually by default /var/lib/mysql But here I give you another “hacky” way to find it out. The method is to find out the mysql daemon mysqld’
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Tag: mysql
How to write a SQL to replace strings in a column in a MySQL database table?
Posted onHow to replace strings in a column in a MySQL database table? For example, I would like to replace http://www.systutorials.com with https://www.systutorials.com in a content column of a table post. You may use a SQL statement as follows. update post set content = replace(content, ‘http://www.systutorials.com’, ‘https://www.systutorials.com’) where content like ‘%http://www.systutorials.com%’
How to show N entries in result of a select SQL query to MySQL?
Posted onHow to show only N entries in the result of a select SQL query to MySQL? The select SQL query is: select * from qa_users; To limit the N entries (say N = 10), we can use the limit clause as follows. SELECT * FROM qa_users LIMIT 10; Note that it is for MySQL. For
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how to integrate MySQL client into self designed database
Posted onCurrently, I need to integrate MySQL client into SQLE as SQLE’s client. And then, we just need design/implement a translation layer to transfer MySQL protocol into SQLE engine part (KV+ internal exactly). Mysql-Proxy could solve this problem but it is complex to be only a MySQL server. Therefore, I remoduled MySQL-proxy to be more simple
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HTML form generation from the database and store value into the database
Posted onI have a “t_form” table and a “t_attribute” table. It looks a little bit like below. Form table form_id | form_name | description ———————————– 1 | Laptop | Possible attributes are Model, Screen Size, OS, Cd Player 2 | Mobile | Possible attributes are Model, OS 3 | Tablet | Possible attributes are Model, Screen
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How to count the number of page view
Posted onI have seen the question Better way to count total page views? I think, the better way is.. We can save the number of page views in the database. It is acceptable. But, it is not fulfilling my requirement, if many different users can appear to have the same IP Address (e.g, if they are
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How to set up MySQL replication
Posted onHow to set up MySQL replication. And for debugging purpose, it will be great if I can run multiple MySQL instances on a single host. To set up MySQL replication, check these tutorials: MySQL Replication MySQL replication setup You can Setup multiple MySQL instances on single server.
How to find out and change the storage engine of tables in MySQL
Posted onHow to find out and change the storage engine of tables in MySQL databases? Find out the storage engine of a table in a database: SELECT ENGINE FROM information_schema.TABLES WHERE TABLE_SCHEMA = ‘database’ AND TABLE_NAME = ‘table’ Change the storage engine of a table: ALTER TABLE table ENGINE = type type can be innodb or
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How to change strings in MySQL tables
Posted onHow to change strings in MySQL tables? e.g. I want to change domain.com to www.domain.com. Use the REPLACE functions of MySQL: http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_replace One example is like this: UPDATE table SET field = REPLACE(field, ‘domain.com’, ‘www.domain.com’) WHERE field LIKE ‘%domain.com%’ The WHERE clause is not needed but can make execution faster.
How to install WordPress on Fedora 19
Posted onHow to install the latest WordPress on a newly installed Fedora 19? Thanks! First, install the LAMP (you already have ‘L’) stack: # yum install httpd php php-mysql mysql-server php-gd and start these services: # systemctl start mysqld.service httpd.service Then, install WordPress on the LAMP stack following the tutorials on the Web. Two good ones
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How to repair tables database by backup
Posted onHow to repair tables database by backup Is this possible? Please explain how to repair. and thanks This post may help: https://www.systutorials.com/qa/300/how-to-repair-a-mysql-table thanks dear Zhiqiang Ma
MySQL at Facebook
Posted onFacebook uses lots MySQL databases. Any information about how Facebook scales MySQL? Some information on the Web: MySQL at Facebook’s page https://www.facebook.com/MySQLatFacebook?filter=1 A post by Ryan Thiessen, Database Operations at Facebook on Quora: http://www.quora.com/Facebook-Engineering/How-does-Facebook-structure-MySQL-so-that-it-is-robust-and-scalable And more: http://mashable.com/2011/12/15/facebook-timeline-mysql/ http://gigaom.com/2011/12/06/facebook-shares-some-secrets-on-making-mysql-scale/ http://www.wired.com/wiredenterprise/2011/12/facebook-timeline-anatomy “A lot of people are surprised that for this shiny new thing for Facebook, we’re using
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Cache at Facebook
Posted onAbout caching system at Facebook. According to: https://www.facebook.com/notes/facebook-engineering/monitoring-cache-with-claspin/10151076705703920 Facebook has two major cache systems: Memcache, which is a simple lookaside cache with most of its smarts in the client, and TAO, a caching graph database that does its own queries to MySQL. The NSDI’13 paper introduces more about Memcache: https://www.usenix.org/conference/nsdi13/scaling-memcache-facebook The USENIX ATC’13 paper introduces
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How to repair a MySQL table?
Posted onAfter a server crash and restarting, MyBB reports a SQL Error as follows: MyBB SQL Error MyBB has experienced an internal SQL error and cannot continue. SQL Error: 145 – Table ‘./mybb/mybb_sessions’ is marked as crashed and should be repaired Query: SELECT * FROM mybb_sessions WHERE sid=’40021925bd0494ea31…’ AND ip=’x.x.x.x’ LIMIT 1 The dababase is MySQL.
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How to install and configure a MySQL cluster on CentOS/RHEL 6.3?
Posted onAny good tutorial on how to install and configure a MySQL cluster on CentOS/RHEL 6.3? Check these posts: Installing MySQL Cluster on CentOS 6.3Configuring the MySQL Cluster General tutorials: MySQL Cluster Installation and CentOS 6: Install MySQL Cluster – The Simple Way.
How to Connect to MySQL in JSP
Posted onWe use tomcat as the container used for instructions in the post. 1) Download the driver mysql-connector-java-*.*.*-bin.jar and put it into WEB-INF/lib/, and remember to restart tomcat. 2) The example code as follows. String driverName=”com.mysql.jdbc.Driver”; String userName=”username”; String userPasswd=”password”; String dbName=”dbname”; String tableName=”tablename”; String url=”jdbc:mysql://localhost/”+dbName+”?user=”+userName+”&password=”+userPasswd; Class.forName(“com.mysql.jdbc.Driver”).newInstance(); Connection conn=DriverManager.getConnection(url); Statement statement = conn.createStatement(); String sql=”SELECT *
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A Free Personal WordPress Blog Solution
Posted onIf you want to have a wordpress blog for FREE co.cc + x10hosting is the best choice. I will introduce both in this post. I will briefly introduce how to set up a wordpress blog like my blog. The overall that I paid for this blog is only $0.89. I can say that it is
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