MySQL

MySQL parameter file is----MY.CNF How to determine which of the database reads, the command gives the answer[[email protected] home]# MySQL--help |grep my.cnfOrder of preference, MY.CNF, $MYSQL

MySQL database with RPM package after installation, a series of problems, the following will start to answer1. After the installation is complete, service MySQL start, normal startUse MySQL or mysql-u root-p to enter directly, the following error is

Cluster query is the object of the table is one of the columns, such as the following TestTable table, to find out the username column, the number of occurrences of each item, then use the cluster queryObviously, after the cluster query, the results

I may have used the stupidest method in the world, but after all kinds of attempts, it was finally possible.The first step is to copy the data file from the MySQL installation directory to your custom path.Chown-r Mysql:mysql/mnt/mysqldata (This is

MySQL turns timestamps into common time formatsIn MySQL, the storage type of a time field is int (11), and how to convert it into a character type, for example, to store 13270655222, needs to be converted to YYYY-MM-DD form.Use the From_unixtime

phpMyAdmin is a PHP -based , Web mysql/mariadb Database administration Tools. Although there are already some such as Adminerof lightweight database management tools, butPhpMyAdminis also more widely used by webmasters to perform

After installing MySQL, if you need to connect remotely, you need to do some configuration, otherwise there will be some similar errors, such as1045 (28000):1045 (28000) MySQL telnet 2003Can not connect to MySQL error 100611 "Can not connect to

1. View the number of concurrent requests for the Web server (Nginx Apache) and its TCP connection status:Netstat-n | awk '/^tcp/{++s[$NF]} END {for (a in S) print A, s[a]} 'Or:Netstat-n | awk '/^tcp/{++state[$NF]} END {for (key in) print key, "T",

1. Install the database, configure the master, and then keepalivedDatabase Installation CompleteYum install mysql-server yum install Mysql-devel========================================================[[email protected] ~]# rpm-qa|grep

1, the use of cursorsBEGIN DECLAREDoneINT DEFAULT 0; DECLAREUseridINT; DECLARERsCURSOR for SELECT' UID ' fromSinbegin_userWHEREService= 0;/*Defining Cursors*/ DECLARE CONTINUEHANDLER forSQLSTATE'02000' SETDone= 1;/*Exception Handling*/

1. Error descriptionOrg.hibernate.exception.DataException:could not execute Statementat Org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert (sqlexceptiontypedelegate.java:69) at

Mysql> Show variables like ' character% ';+--------------------------+----------------------------+| variable_name | Value |+--------------------------+----------------------------+| character_set_client | UTF8 || character_set_connection | UTF8 ||

Update syntaxSingle-table Syntax:UPDATE [low_priority] [IGNORE] tbl_name SET col_name1=expr1 [, col_name2=expr2 ...] [WHERE Where_definition] [ORDER by ...] [LIMIT Row_count]Multiple-table Syntax:UPDATE [low_priority] [IGNORE]

MySQL Slow query1. What is the use of slow queries?It records all SQL statements that execute more than long_query_time time, helping you to find SQL that executes slowly, so we can optimize these SQL.2. How do I turn on slow queries?First we check

Method One:SELECT Z.zone_id,z.name,z.code,z.other_name from T_sys_zone ZWHERE CONCAT (', ' (SELECT ZI. Incharge_zone from T_crm_sales_incharge_zone ZI WHERE z.sales_men=7), ', ')Method Two:SELECT Z.zone_id,z.name,z.code,z.other_name from T_sys_zone

Installing a standalone version of MySQL5.6.23 in a CentOS7 environmentSince MySQL needs to rely on Perl's package, install Perl using the following command first1. Yum Install perl*Installing Mysql-client2. RPM-IVH mysql-client.rpmSince

Import text files to mysql database tables and insert commands to insert data to tables 1. Import a text file to a database TABLE: mysql> load data local infile 'text path 'into TABLE name; example: mysql> load data local infile 'd: /pet.txt

Php cannot connect to mysql Background: Use lighttpd as the web server, php as the server script, and mysql as the database. When accessing the browser client, the server php script will try to connect to mysql, query the data and return it to the

Common mysql database commands1. Database authorization Go to the mysql database: mysql> use mysql; set a new password for the root user: mysql> update user set password = password ("new password") where user = "root "; refresh the database mysql>

Design and use of mysql IndexesOverview The index is used to quickly find rows with a specific value in a column. If no index is used, MySQL must start with 1st records and read the entire table until related rows are found. The larger the table,