MySQL

MySQL Incremental recovery processCreate a table for testingMysql> CREATE table User (name char (ten), age int (3)); Query OK, 0 rows affected (0.07 sec) mysql> desc user;+-------+----------+------+-----+---------+-------+| Field | Type | Null | Key

A site that uses a MySQL database, "Too many connections" error occurs when there are too many access connections. There are two cases of this error, one is that the Web site access is too large, the server can not afford, at this time should

Select curdate(); --Get the current dateSelect Last_day(curdate()); --Get the last day of the month. Select Date_add(curdate(),interval - Day(curdate())+1 Day); --Get the first day of the monthSelect Date_add(curdate()- Day(curdate())+1,interval 1

1. Check the MySQL character setting: If it is not GBK, make the relevant settingsMysql>set character_set_client =gbk ;Mysql>set character_set_connection = gbk;Mysql>set character_set_database = gbk ;Mysql>set

Mysql> Show index from tblname;mysql> show keys from tblname; The name of the table sheet. Non_unique 0 If the index cannot include a repeating word. 1 if it is possible. · The name of the Key_name index. Seq_in_index the column sequence number in

Remember a very long SQL, in order to facilitate reading, I have added the paragraph: SELECT * from ( (SELECT 1 asAcheck, S1.id, S1.plan_name, S1.cost_mode, S1.sta_type, S1.cost_type, S1.cost_period_time, S1.cost_period_value, S1. '

[Understanding Index]To understand an index, you first need to understand how the data is stored on your hard disk. Different storage engines may not take the same action, for example, the MySQL client defaults to MyISAM, which creates a separate

Sometimes you write your own tools to get a variety of table information from a remote database, so you get the data dictionary first.Make a list of how MySQL gets Use Information_schema; Select from schemata; Select from where

Heartbeat+drbd+mysql High-availability1. Planningvip:192.168.1.30Myhost1:Intranet ip:192.168.1.11Heartbeat Heartbeat ip:192.168.74.11DRBD Transport ip:192.168.223.11Myhost2:Intranet ip:192.168.1.12Heartbeat Heartbeat ip:192.168.74.12DRBD Transport

Think of a question:1/3+1/3+1/3=1.00.3+0.3+0.3 =0.9Think about what it means to be 1/3 in a decimal world! Its approach is to take a 1/3 very close to the decimal place, as in the example above the 0.3来 instead of 1/3, so the problem is to be stored

Create a test tablemysql> desc; +-------+-------------+------+-----+---------+----------------+| Field | Type | Null | Key | Default | Extra |+-------+-------------+------+-----+---------+----------------+| ID int(one) | NO |

First, the main advantagesThe concept of dual-machine hot standby simply say, is to maintain the status of two databases automatically synchronized.Operations on any one database are automatically applied to another database, keeping two of the

Login: Mysql-uroot-p-p3306-h----(-u means user name,-p for password, can not lose,-p for port number,-H for Host name)Show current server version: SELECT version ();Show current date time: Selectnow ();Show Current User: SELECT user ();Create a

For English, MySQL's Fulltext property is quite convenient and efficient to implement full-text retrieval, but there are some things to be aware of in the process of using.First, we add the Fulltext attribute to the field we need to retrieve

MYSQL database Naming and Design Specifications1. Design Principles 1) standardization and standardizationData Standardization helps eliminate data redundancy in databases. There are several forms of standardization, but Third Normal Form (3NF) is

The founder of the technology company talked about the future of MySQL As the stable version of MySQL 5.7 is approaching its official release, we have joined various MySQL branches to continue to compete for market share. We interviewed Peter

Lost connection to MySQL server at 'reading authorization packet 'Solution Mysql Version: 5.1.73 OS Version: Centos 5.9 Problem description: Today, an error is reported when a php program connects to Mysql from a client. The information is as

MongoDB and MySQL operations On the left is the mongodb query statement, and on the right is the SQL statement. It is easy to use. Db. users. find () select * from users Db. users. find ({"age": 27}) select * from users where age = 27 Db. users.

Mysql Chinese garbledAlthough mysql is installed on the computer, I have never studied the problem of modifying the encoding. I usually use Pinyin instead of Chinese characters, because I am doing some simple syntax exercises, I am not very

Explore paging performance-mysql Paging technology is very common in development. I used paging technology for the two projects I just joined the company, so I thought about in-depth exploration of paging technology. Several common paging