MySQL

Operating system: Windows7MySQL version: 5.5.22Www.jb51.netWhen using the command mysqld--install servicename--defaults-file= ' file_name ' to create a MySQL service, the systemThe creation service was prompted for success, but the net start command

In Navicat for Mysql,postgresql and Oracle The error occurred because the MySQL account does not have sufficient permissions to connect to the remote MySQL server. Only "localhost" connections are allowed by default after MySQL installation.

First, connect MySQL Format: mysql-h host address-u user name-P user Password 1, connected to the MySQL on the computer. First open the DOS window, and then enter the directory Mysql\bin, and then type the command Mysql-u root-p, enter after the

The reason that MySQL appears garbled To understand why there are garbled, we must first understand: from the client request, to MySQL storage data, and then the next time from the table to retrieve the client process, which links will be

In the last two articles (MySQL backup and restore cold standby, MySQL backup and restore real-world use Lengbei), we mentioned the use of cold standby in the Lengbei and real environment. So starting from this article, let's look at the hot standby.

A federated index is also called a composite index. For composite indexes: MySQL from left to right using the fields in the index, a query can use only parts of the index, but only the leftmost part. For example, the index is key index (A,B,C). can

MySQL's default encoding is Latin1, does not support Chinese, to support Chinese need to change the database's default encoding to GBK or UTF8. 1, need to log in as root user can view the database encoding (as root user login command: >mysql-u root–

Start a connection using MySQL binaryyou can use MySQL binary to enter the MySQL command prompt to connect to the MySQL database.InstanceThe following is a simple example of connecting to a MySQL server from the command line: [root@host]#

The recent use of MySQL database has encountered many types of numbers, mainly int,bigint,smallint and tinyint. Among them, the difference between int and smallint is confusing. Today on the internet carefully looked for, find the following content,

This article looks at a case to see how the MySQL optimizer chooses the index and join order. Table structure and data preparation refer to the last section of this article, "Test environment." The main implementation process of the MySQL optimizer

Installation To make the article more complete, we choose to install MySQL from the source code, it is important to note that the early version of the memory leak, so the recommended installation of the latest stable version, as of this article,

We have seen the SQL SELECT command using the WHERE clause to fetch data from the MySQL table. However, when we try to give the condition to compare the value of the field or column to NULL, it does not work correctly. To handle this situation,

Today, watching a Shuiyu said that his MySQL is now very slow. Asked what the situation was. Say one myisam of more than 2 G in a single table. The answer to the real rubbish. Simple answer: Switch to a strong server. Changing the server is very

Using Perl to connect to MySQL, there are many cases on the Internet, and generally we are dbi under the Dbd::mysql this module. Here make a mask get a tips:Perl DBI MySQL's character set is UTF8Perl DBI special characters write times wrongPerl DBI

Received a MySQL server load alarm, up a look, load average are more than 280, with top look, the CPU ran to 336%, but IO and memory load is not high, according to experience, should be an index caused by the tragedy. Look at the processlist and

First, the preface Many articles will say that the permissions of the database according to the principle of minimum authority, this sentence itself is not wrong, but it is an empty words. Because of the least privilege, this thing is too abstract,

The MySQL system creates temporary tables in memory (MEMORY) and disks (MyISAM), how do you know how many temporary tables are built on disk, and how many temporary tables are built in memory? You can learn from the following commands: Mysql>

Server System Variables The server maintains a number of system variables that represent its configuration. All variables have default values. You can set them on the command line or option file Setup options when the server starts. Most can be set

Background In normal development, often encountered this update data scenario: first to determine whether a data in the library table exists, there is update, does not exist insert.If you use Hibernate, it takes a saverorupdate method and is

MySQL in the can ' t specify target table for update in the FROM clause error means that you cannot select some of the values in the same table first, and then update the table (in the same statement). For example, the following SQL: Copy Code