MySQL

Mysql function instance-count the daily retention rate 1. the database table stores the information of mobile users in a visitor_user table, which contains the data that users can obtain when using the mobile app software, including: merchant id,

The script that checks whether mysql master and slave are normal is learning myslq master and slave, and wants to use a simple script to test whether the master and slave are normal. 01 #! /Bin/bash0203while getopts "h: u: p: P:" arg # The colon

In mysql, LIKE is used. Regular LIKE % indicates any occurrence of any character (except NULL) (0 -- infinite ). Note the case sensitivity. _ Indicates that any character appears in the regular expression 1 (not many or less) ^ $. (match any single

DATE_SUB (NOW (), INTERVAL 5 MINUTE) and DATE_FORMAT (DATE_SUB (NOW (), INTERVAL 5 MINUTE), '% Y-% m-% d % H: % M: % s') [SQL] [root @ CactiEZ ~] # Time mysql-h 172.22.10.32-ucacti-P3316-pcacti-e "select count (*) from order. tbl_tieyou_order where

Mysql5.5.23 TYPE = InnoDB syntax error Create table if not exists 'ad _ aXXXX_test_delete '('payment' double () default '0. 0000 ', 'createdatetime' timestamp not null default '2017-00-00 00:00:00', primary key ('aspid ', 'date') TYPE = InnoDB; you

MySQL select limit specifies the number of rows to query MySQL, which is the most widely used database. It is known for its lightweight, open-source, and efficient nature. Once a product owned by SUN, as SUN was acquired by Oracle, MySQL was also

Install MySQL-source code (for testing in an experimental environment)[Plain]# The virtual machine is the original system. We have installed scp in the virtual machine.[Root @ serv01 ~] # Yum install/usr/bin/scp-y# Installation Process# Copy the

Mysql Note 1. Disable query cache. query_cache_size = 0. 2. Innodb tables are saved in the order of primary keys. Therefore, sorting imported data in the order of primary keys can effectively improve the efficiency of data import. 3.

Find out slow SQL of mysql Recent days, I shocould do a SQL tuning for a mysql database, and I know a bit of mysql db. in order to find the slow SQL, I do the slow_query_log on to collect the slow SQL. [sql]mysql> show variables like 'slow%'; +-----

Functions and keywords used By MySQL advanced query and Group By set: 1 GROUP_CONCAT mysql> SELECT student_name, -> GROUP_CONCAT(test_score) -> FROM student -> GROUP BY student_name;Or:mysql> SELECT student_name, -> GROUP_

What is MySQL view is a virtual table whose content is defined by the query. Like a real table, a view contains a series of columns and row data with names. However, a view does not exist in the database as a stored data value set. Rows and columns

Mysql enable remote access permission using the root user to log on to mysql 1. Execute the following command in the mysql command line: [plain] # mysql> grant all privilegeson *. * TO 'root' @ '%' with grant option; 2. restart the mysqld service: [

Sort out common mysql monitoring scripts 01 #! /Bin/sh02 # filename: mysql_monitor.sh03 # site: www. jbxue. com04 # Check whether mysql server provides services normally 05 mysqladmin-u sky-ppwd-h localhost ping0607 # obtain the current mysql Status

The usage and difference between having and where statements in mysql we often use where statements when writing SQL statements, and having is rarely used, in fact, the having clause in mysql is also a set condition statement similar to where but

It takes 8 minutes for mysql to create and delete indexes... current Environment: -------------- table row: 30W version 5.0.45-community-nt System XP CPU2.11G MEM2G test statement :---------------------- Create index I _atian ON gaopinzi (atian)

Big file cross-network transmission skills O & m dba cross-network transmission of large files, such as the same as the kitchen in the toilet, the general good method is not obvious, and the advantages and disadvantages of the method may be very

How can I solve the deadlock issue in MYSQL? Find the original lock ID and KILL the thread that has been held all the time. But how can we find the thread ID that causes the deadlock among many threads? MySQL has been very powerful since its

Show processlist result filtering in MySQL the show variables where variable_name like '% auto %' statement can be executed normally, but the show processlist where host like '% 100' error will be reported: error Code: 1064You have an error in your

When inserting data in MYSQL, duplicate data is ignored. when inserting data in the program, existing data is not inserted, and non-existing data is inserted. You can use the stored procedure or not exists to determine whether the stored procedure

MySQL 5 Exception Handling 1. sample Problem: Log Of Failures example: When the INSERT operation fails, I want to record it in the log file. It is common to show the error handling example. I want to get an error record. When the INSERT operation