MySQL

Recently, I am working on a large concurrent project and tried InnoDB's Installation File of MySQL5.5 and less than 30 m, which is no inferior to the huge Oracle or MSSqlServer. We believe that MySQL is widely used in Windows because it is

Records in the error log:[ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql. host' doesn' t existI posted a post. I only saw it, but no one replied. I can only solve the problem by myself. Can I help myself... You don't have to

Next article: mysql uses mysql-udf-http Efficiency Test notes. Instead of using the rest architecture, this time it uses libmemcached and memcached_functions_mysql. The test version is:Libmemcached-0.34.tar.gzand memcached_functions_mysql-0.9.tar.gz

If you want to connect to your mysql instance, this error occurs:Copy codeThe Code is as follows:ERROR 1130: Host '192. 168.1.3 'is not allowed to connect to this MySQL server Solution:1. Change the table. It may be that your account is not allowed

The following is the main content of the article.1. SELECT * FROM 'table' order by rand () LIMIT 5You can.However, the test results show that the efficiency is very low. It takes more than 8 seconds to query 5 data records in a database with more

Ultimately, the following solutions are provided:1. Clear the installation directory of MYSQL. The default value is C: \ Program Files.2. Clear the MYSQL Data storage directory, which is generally in the C: \ Documents and Settings \ All Users.

To achieve this effectIf a group by condition is used, the results will be much less. How can I combine multiple conditions for filtering?Copy codeThe Code is as follows:Group by fielda, fieldb, fieldc... During the loop, you can determine whether

For large systems, Oracle and SQLServer are undoubtedly the best choice. You can see that there are more and more small websites. They don't have their own servers, just buy others' space and databases, however, the performance of such a small

Problem: when the short message is reviewed, it will be determined based on the content. For example, if the content of a can pass, and the content of B cannot pass, MySQL displays msg = a, msg = B, however, if the content of the msg field contains

SQL statement:Copy codeThe Code is as follows:Update item I, resource_library r, resource_review_link l set I. name = CONCAT ('review: ', r. resource_name) where I. item_id = l. instance_idAnd l. level = 'item' and r. resource_id = l. resource_id

The following describes how to create a data and a user. The graphic operation principle is the same as the command line principle.Navicat 8 Lite version (7 M) MYSQL image management tool V8.0.28Step 1: connect to mysql first. If the connection

Two MySql service applications1. How to install two MySql services on the same system.Install Version 5.0, and then Install Version 5.1. I am using mysql-5.0.45-win32.zip and mysql-5.1.28-rc-win32. Note that the Configuration Port Number installed

Environment variable settings: Right-click my computer on the desktop and choose Properties> advanced> environment variables> double-click the Path to add the C: \ MySQL5.1.40 \ bin directory. If you want to use SDK development, add the Lib and

You only need to follow the three steps below, and everything is under your control:Step 1: configure the Backup Directory code on the server:--------------------------------------------------------------------------------Mkdir/var/lib/mysqlbackupCd/

I. Preface: After the database server is set up, the first thing we need to do is not to consider which MySQL-initiated programs should be run on the server that supports the database, but when the database is damaged, how to safely restore to the

// I modified it to run normally. The test environment is mysql5.0 and xp.// The key is to set the character set, set gbk, gb2312 to pass the test, and utf8 to fail.// Create a database jj before running the program. Pay attention to the following

1. InstanceCopy codeThe Code is as follows:DELIMITER //Drop procedure if exists 'test'. 'P _ getvalue '//Create definer = 'root' @ 'localhost' PROCEDURE 'P _ getvalue '(In id varchar (20), out s varchar (20))BeginIf (length (id) = 11) then select 'A

Example:Copy codeThe Code is as follows: Generally, lazy is set to true instead of false, because if it is set to false, the corresponding sub-table will also be queried while querying the master table, added a lot of useless work.

Mysql> use test;Database changedMysql> create table shop (-> Article INT (4) unsigned zerofill default '100' not null,-> Dealer CHAR (20) DEFAULT ''not null,-> Price DOUBLE (16, 2) DEFAULT '0. 00' not null,-> Primary key (article, dealer ));Query OK,

The database file is large, about 70 GB,For normal migration, You need to export data in the original database and then import data in the new database.After careful consideration, is the format of MySQL database file storage identical in different