MySQL

On the remote host, I opened the MySQL service, the command line can be opened, such as the user named Root, the password is 123456. However, the remote connection with the Mysql client is reported error, such as Mysql-front reported the following

Download Linux generic version tar.gz file, such as: mysql-5.7.18-linux-glibc2.5-x86_64.tar.gzUnzip to the target directory, such as:/test/mysql-5.7.18-linux-glibc2.5-x86_64Mkdir/test/mysql-5.7.18-linux-glibc2.5-x86_64/dataCd/test/mysql-5.7.18-linux-

1. Adding and deleting to seal the mysqlhelper.py1 ImportPymysql as PS2 3 classMysqlhelper:4 def __init__(self, host, user, password, database, CharSet):5Self.host =Host6Self.user =User7Self.password =Password8Self.database

#!/usr/bin/env python# Coding:utf-8import mysqldbimport requests, jsonimport Timeurl = "Http://api.sendcloud.net/apiv2 /mail/send "key = {}params = {} #目标用户的邮箱to_email = {' Root ': [" [email protected] ",], ' Tianyi ': [" [Email protecte] D] "

1.crontab-e #编辑属于当前用户的定时任务.2. Edit: Key I: Writing tasks such as: */1 * * * */usr/local/hy_mysql/bin/mysqldump-uroot-proot--socket=/tmp/mysql3305.sock Test DM001>&G T /usr/local/sql_bak/dm001.sql >/dev/null 2>&1 #每隔一分钟导出数据库中的数据.3. Press ESC---": Wq #

1. Background * Full and query results merge the query results of multiple SELECT statements together. * Result sets that participate in merging require field unification. * fields can be replaced with an empty string '. 2. Merge query results

Reprint: C Blog: Lone MaleUse a configuration file to connect to the database, which is the professional term for connection pooling.The connection pool is responsible for assigning management and freeing the database connection, which allows the

MySQL primary master replication schema ConfigurationReprint: Original source http://luoweiro.blog.51cto.com/2186161/658550The MySQL master replication structure differs from the master-slave replication structure. In the primary master replication

Migrating from one database data to a local localhostThe program in the call to the database view times wrong, directly open the view in the database also error, similar to:MySQL 1449:the user specified as a definer (' montor ' @ '% ') does not

1005: Failed to create TABLE 1006: Failed to create database1007: Database already exists, database creation failed1008: Database does not exist, delete database failed1009: Unable to delete database file causes database failure to be deleted1010:

Grammar:end Repeat;is equivalent to that in other languages:do{# }while ();Mysql> Create procedurep1p () - begin - Declare Count int default 0; -Repeat - Select User(); - Set Count = Count + 1; -UntilCount>3 Endrepeat; -

The default global variable is two@@ 开头, you can view all default variables with show variables:@ @user#declare定义变量只能用在储存过程中 #Declare Variable namedata type Optional typeDeclare Num int;Declare Age intDefalut -; #定义全局变量, can be declared with set: #@

Let's take a look at the two tables of the experiment:Table comments, Total row number 28856 table Comments_for, Total row number 57,comments_id is indexed, ID is listed as primary key. The above two tables are the basis of our testing, and then

1,shell Common Variable parsing:The name of the current script$n the nth parameter of the current script$* all parameters of the current script (excluding the program itself)$# the number of arguments to the current script (excluding the program

in a multiuser environment, multiple users may update the same record at the same time, which can create a conflict. This is the famous concurrency problem.Typical conflicts are:1. Missing updates: One transaction update overwrites the update result

Group_concat function in MySQLThe complete syntax is as follows:Group_concat ([DISTINCT] field to connect [order by Asc/desc sort field] [Separator ' delimiter '])Basic QuerySQL code SELECT * from AA; +------+------+| id| name |+------

P131) When you create a table, the default engine is InnoDB, and if you want to modify the default storage engine, you can set default-table-type in the parameters file. To view the current default storage engine, you can use the command:When

integral type (int tinyint)tinyint created by default is a signed1, control mostly small is controlled by the type, not the latter int (2) to control, he does not mean as long as two bits. (on behalf of 0 fills)Int (m): M indicates the maximum

InnoDB consists of several componentsFirst, Innodb_buffer_pool:1 It is primarily used to cache data and indexes (precisely because the tables in InnoDB are organized by a clustered index, so the data is not the leaf node of the index of the primary

MySQL functions-other functions, mysql Functions IF (expr, v1, v2) expr expression is true, v1 is returned; otherwise, v2 is returned. IFNULL (v1, v2) If v1 is NULL, v2 is returned. If v1 is not NULL, v1 is returned. CASE expr WHEN v1 THEN r1