MySQL

Windows--mysql Zip version installation record: Step1. Official website Download Zip Package: http://cdn.mysql.com//Downloads/MySQL-5.7/mysql-5.7.10-winx64.zip Step2. Unpack the package, add E:\software\mysql-5.7.10\bin in Path

Recently on MySQL to build some data, involving random numbersThis is the creation of a 8-bit random string, with numbers and characters, created by the UUID.SET @bian = (select Left ((select REPLACE (UUID (), '-', ')), 8)); Create a random

The reason is not clear, first record.Use the DateDiff function to calculate a time difference of two dates. In MyBatis, Resulttype is a map. In the code, depending on the value of the map key.In MySQL 5.5.39, the resulting type is an integerIn

To create a user:' username '@'host'password';Description: username– You will create the user name, host– specifies which host on which the user can log on, if localhost is available to local users, you can use the wildcard% if you want the user to

The following is a detailed description of the issues that need to be noted in writing the WHERE clause of some SQL statements. In these where clauses, even if there are indexes on some columns, because poor SQL is written, the system cannot use the

1. Principle[3 Threads complete Master-slave replication]Master Library A thread is responsible for logging database change logsA thread from a library is responsible for pulling the change log of the main libraryOne thread from the library is

LAST_INSERT_ID () is a value that MySQL provides to return the last insert or update query set to the Auto_increment column in the current clientLAST_INSERT_ID () is not affected by other clients, so is thread-safe, the current client can only get

When MySQL builds a table, there are three options for each field's properties: binary,unsigned,unsigned Zerofill, which functions as follows:CHAR VARCHAR: Values are sorted and compared in a case-insensitive manner based on the default character

The following error occurred connecting to MySQL:ERROR 2002 (HY000): Can ' t connect to local MySQL server through socket '/tmp/mysql.sock ' (2)Thought the wrong place, the cache file exists under the TMPOn the Internet to check the cause of the

(1) First create the text file, (where created can) modify the suffix named Bat file, if your computer does not set the display suffix name, first by left click on My Computer, "view", "File extension", and so you have successfully modified the

SHOW STATUS like '%table_locks% 'Table_locks_immediate | 105 |table_locks_waited | 3 |If the value of the table_locks_waited is higher, then there is a more serious table-level lock contention condition. At this point, we need to do a further review

Two Linux systems install the same version of the MySQL database.Configuration of two databases it must be different to enable both binary logs and Server-id,server-id.Then restart the MySQL database.Authorization to slave from the database

1. Order of Inquiry conditionsWhen there are multiple query conditions, the criteria for more efficient, high-energy and more accurate filtering of records are placed behind. Because MySQL parses the SQL statement from the back forward (not knowing

There are several reasons for garbled problems, one of which is because MySQL uses the iso-8859-1 (or Latin1) character set by default, while Java internally uses Unicode encoding, so when inserting data into the MySQL database in Java, or when

MySQL database optimization (bottom) high-availability architecture scheme for MySQL database 2011-03-09 08:53 fuqin wine 51CTOfont Size:T | T In the last MySQL database optimization, we followed the author to learn the optimization of

Record memo, initial data is as follows:DROP TABLE IF EXISTSt_demo_product;CREATE TABLE IF not EXISTSt_demo_product (proidint( -), Pronamevarchar( -), priceint(Ten), PRIMARY KEY(proid)) ENGINE=InnoDBDEFAULTCHARSET=GBK;DROP TABLE IF

Mysql garbled solution and mysql garbled Solution Symptom: the following error is reported when the data inserted to the database contains Chinese characters.The cause is: the default encoding of the computer is gbk, And the encoding method

Summary of restoring MySQL master-slave data consistency, mysql master-slave This morning, my colleague told me that the data in the MySQL master-slave database was inconsistent and he guessed that the slave database encountered a problem during

Hibernate (9) many-to-many Association and hibernate multiple-to-many Association I. Multi-to-many unidirectional Association Assume that a teacher teaches multiple students and a student is taught by multiple teachers. This is a typical

Will movelob affect other index statuses? The upgrade was performed at the customer's site a few days ago, and the lob field was moved in the script. When the customer continued to perform the operation, the index was invalid. After checking that