MySQL

The error is as follows:This error is a SQL thread error, because Relay-index.index and relay-log inside the file path does not correspond.Workaround: mysql> stop Slave;mysql> Reset Slave;To reassign the main library informationMysql> Change

in the actual work we often need to format the numbers, such as the 12.0073233 into 12.01 , or put A into 12.00 , or put A into 0000012 , the conversion between this format is summarized as follows:One, floating point conversion--Directly set the

Review common points of knowledge in MySQLBoot off service mode for win version. Connect mysql command: mysql-u alex-p View all databases: show databases;use db_name; switch database show tables;  Show All tables select * from table name; Select

From the official website https://dev.mysql.com/downloads/mysql/Download Mysql-5.6.31-winx64.zip, unzip it, the next installation is to install the MySQL database by command. (The version of P.S. 5.7 will be problematic, preferably a 5.6 version)(1)

MySQL's binary log is the most important log of MySQL, it records all the DDL and DML (except the data query statement) statements, logged as an event, and also contains the time spent by the statement, MySQL binary log is transaction-safe. in

Conclusion:When MySQL is in an int type, the search condition where num= ' 111 ' and where num=111 can use the index of the field.When MySQL field is a varchar type, the search condition where num= ' 111 ' can use the index, where num=111 can not

MySQL Installation: at command-line input sudo apt- get install Mysql- server   A window will pop up during installation, enter the password for the database root user ( must enter password )      

MVCC (multiple version Concurrent control) Multiple version concurrency control does not have a unified implementation standard. MVCC can be thought of as a variant of a row-level lock, but in many cases it avoids lock-up operations and is less

MySQL service failed to start, you can use the exclusion method to find the cause:If you modify the MY.CNF after restarting the MySQL service fails, in most cases the configuration file has errors,By backing up the original configuration file and

Introduction to Essentials1. Introduction2. Integer type3. Floating-point types4. String Type5. Time and date6. Collection type1. IntroductionData types play a fundamental but important role in the database, so the choice of data types will affect

An Introduction Two Insert data inserts Three Update operations update Quad Delete operation Delete Five query Operations SELECT An introductionIn MySQL management software, you can use the DML language in SQL statements to

A system databaseINFORMATION_SCHEMA: Virtual library, do not occupy disk space, storage is the database startup parameters, such as user table information, column information, permission information, character information,

Introduction to Essentials1. Introduction2. Data Files3. log Files1. IntroductionThere are at least two operating system files per MYSQL database: One data file and one log file.Data files contain data and objects, such as tables, indexes, stored

What is MySQL master-slave synchronization?Synchronize data from the library on the main library (to have other database servers automatically synchronize data on the data server that is currently being accessed)Structure type of master-slave

What do you mean businessA transaction is a set of operations units of SQL, either the operation succeeds or all fails.Acid attribute atomicity (atomicity)A thing must be considered as an inseparable minimum unit of work, the entire transaction

1. How to solve the problem of master-slave replication delay? (1) Principle of master-slave copying Http://www.cnblogs.com/jenvid/p/8410922.html 1.salve execute slave start,salve service IO thread will connect to master via

Restart the server and restart app service (confluence)-Error, database connection failed (MySQL set boot-up)-View MySQL database status:[Email protected] localhost~]# Ps-ef | grep MySQLRoot 25555 21974 0 11:28 pts/0 00:00:00 grep mysqlstart the

System:CentOS Release 6.5 (Final)Kernel:2.6.32-431.el6.x86_64MySQL version:5.5.28-log Source DistributionOperation Steps:1. Stop the MySQL service#service mysqld Stop2. Enter MySQL in safe mode#mysqld_safe--skip-grant-tables &#mysql-u root-p \ The

First, CREATE table 1, create a new table#语法: Create TABLE table name (field name 1 type [(width) constraint], field name 2 Type [(width) constraint], field name 3 Type [(width) constraint]); #注意: 1. In the same table, the field names cannot be the

(1) List all installed RPM package# Rpm-qa | grep mariadbmariadb-libs-5.5.50-1.el7_2.x86_64mariadb-5.5.50-1.el7_2.x86_64mariadb-server-5.5.50-1.el7_2.x86_64(2) Uninstall# RPM-E Mariadb-libs-5.5.50-1.el7_2.x86_64Error at this