MySQL

Note the encoding consistency, such as: My database is UTF-8 encoding, CSV document encoding is also utf-8.Import use LOAD DATA LOCAL INFILE For detailed usage please refer to documentation or books.MySQL User table structure:+----------+------------

Primary master replication schemaMain service: 192.168.1.84Vice-main service: 192.168.1.851. Main server configuration fileAdd in [mysqld]Sync_binlog = 1A binary file written to disk immediately after any thing is

SQL and index optimization turn on slow query log to see if slow query log is openMysql> Show variables like ' Slow_query_log ';+----------------+-------+| variable_name | Value |+----------------+-------+| Slow_query_log | OFF |+----------------+---

Today, there is a problem with a SELECT statement that does not have an "Order by" and the returned data is indeterminate.This kind of problem has met more than a few times. Traced, if the SELECT statement does not add "order by", how will MySQL be

Extensions: Scale up, scale out.Scaling up is an extension of the server hardware, such as extending from 2 cpu,8g memory to 8 cpu,32g memory.Scaling out takes the form of a master-slave server. Master-slave replication is used for data

One, the CentOS 7.** version cannot install MySQL; Cause analysis:MariaDBdatabase management system isMySQL, mainly by the open source community in the maintenance, adoptionGPLLicense. One of the reasons for developing this branch is that Oracle has

/* UNION */------------------Combines the results of multiple select queries into a single result set.SELECT ... UNION [all| DISTINCT] SELECT ...The default DISTINCT method, that is, all returned rows are uniqueIt is recommended that you enclose

Updating data with UPDATE statement in MySQL error: Lock wait timeout exceeded; Try restarting transaction.This is because the lock on the table you want to update is in the hands of other threads, and if there is no accident, it is likely that the

LAP:Yum Installation:Yum install-y httpd httpd-devel mysql php-devel phpSource Installation:1) Install Apacheyum-y Install Apr-devel apr-util-develCd/data; wget http://mirror.bit.edu.cn/apache/httpd/httpd-2.2.27.tar.gztar zxf httpd-2.2.27.tar.gz; CD

1. Syntax1.1 New functionCreate function function_name (parameter list) returns return value type function Body(1) The function name should be a valid identifier and should not conflict with an existing keyword .(2) a function should belong to a

Delete from test where ID in (the Select ID from (the Select Max (ID) as Id,count (text) as count from test group by text has C Ount >1 ORDER BY count Desc) as tab)Test codeINSERT IGNORE into test_1 (TEXT,TEXT2) VALUES (' 1111 ', ' 22222 '); INSERT

Problem Recurrence (The following discussion is for Windows environments only):C:\appserv\mysql> Mysql-u Root-pEnter Password:ERROR 1045 (28000): Access denied for user ' root ' @ ' localhost ' (using Password:yes) edit mysql config file my.ini

/ * Import and Export */------------- Select * into outfile file address [control format] from table name; --Export table data Load data [local] infile file address [Replace|ignore] into table table name [Control format] ; --Import data The

After deleting the root user in the MySQL users table, we can use the following command to achieve the recovery;2 ways to start the MySQL database safe mode1. Modify the configuration file/etc/my.cf, add--skip-grant-tables2. Use the command to enter

I. Exception information and workaroundsCom.mysql.jdbc.exceptions.jdbc4.CommunicationsException:Communications link Failure     Org.springframework.transaction.CannotCreateTransactionException:Could not open JDBC Connection for transaction; Nested

1. Enter mysql-u root MySQL2.mysql> Status Input Update user set Password=password (' New password ') where user= ' root '; 3. mysql> State input FLUSH privileges; ( This command will update the MySQL system database loaded into memory with the

MySQL MonitoringMySQL server hardware and OS (operating system) tuning:1. There is enough physical memory to load the entire InnoDB file into memory-the INNODB will be much faster if the files are accessed in memory rather than on disk.2, to avoid

Today the project boss raised a SQL statement requirements, I listen to the confused, no way, step by step discussion, practice, finally fix.First build the table statement:1 /*2 Navicat MySQL Data Transfer3 4 Source server:localhost_33065 Source

I. OverviewMySQL is a cross-platform open source relational database management system, currently affiliated with Oracle Corporation. MySQL is widely used in small and medium-sized websites on the internet. Because of its small size, fast speed, low

1, decompression, free installation2, the configuration environment variable, the new variable name mysql_home, the variable value is the MYSQL installs the directory path, C:\Program files\mysql-5.1.69-win32;3, add in the path variable of