MySQL

One, SQL mode SQL pattern matching allows you to match any single character with "_", while "%" matches any number of characters (including 0 characters). In MySQL, the SQL schema defaults to ignoring the case. Some examples are shown below. Note

Because the MySQL database is intended to be reinstalled on a test machine, the process can be thought miserable because of the simple and crude direct uninstall that does not back up the MySQL database used by the company Discuz and Redmine.

1. mysql Database master-Slave synchronization delay principle.To say the principle of delay, from the MySQL database master-slave copy principle, MySQL master-slave replication is a single thread of operation, The main library for all DDL and DML

Yesterday in the group to see a new classmate still asked MySQL can not start the problem, so summed up a few common circumstances, the right when the popularity of the post, the old bird consciously flew. Issue 1: directory, file permissions are

1, the table's primary key, the foreign key must have the index; 2, the data volume of more than 300 of the table should be indexed; 3, often with other tables to connect the table, in the connection field should be indexed; 4, often appear in

1: Numeric parameters force filtering using a method such as Intval,floatval. 2: String parameters Use a method such as mysql_real_escape_string to force filtering, rather than simple addslashes. 3: It is best to discard mysql_query such a

MySQL finds from multiple fields In MySQL, if you want to implement sorting by a field, you can use the following SQL statement SELECT * FROM ' table_name ' ORDER BY ' Field ' However, what if you want to implement sorting by a field and then

InnoDB when writing intensive pressure, due to b-tree extension, it will also bring the expansion of data files, however, InnoDB data file extensions need to use a mutex to protect the data files, which can cause fluctuations. Ding's blog explains

In MySQL, many friends think that the field Auto_increment type ID value can not be modified, in fact, this understanding is wrong, the following describes the MySQL ID's starting value modification and setting method.The usual way to set up a

When inserting records using the Insert SELECT statement, the following guidelines must be followed. When you select data with the SELECT statement, you cannot select rows from the table where the data is inserted. Specifies that the inserted table

Environment: Os:windows 2003 db:mysql5.5 1. Normal installation of the first MySQL (Installation steps omitted) 2. Stop the first MySQL service in the control Panel 3. Copy all directories and files under the C:\Program files\mysql directory to

Mysqld_safe is recommended for use in UNIX and NetWare to start the MYSQLD server. Mysqld_safe adds some security features, such as restarting the server when an error occurs and writing Run-time information to the error log file. The specific

The most common way to execute a GROUP BY clause is to scan the entire table and then create a new temporary table in which all rows of each group in the table should be contiguous, finally using the temporary table to locate the group and apply the

In the process of using MySQL, there is a problem is the optimization of MySQL, MySQL in the Longblob field in version 5.5 of the default for 1M. To change this problem, you need to pay attention to a few points:

1, install the MySQL has InnoDB plug-in expansion ./configure--prefix=/usr/local/mysql--with-plugins=csv,innobase,myisam,heap,innodb_plugin 2, the column referenced in the main table could not be found 3, the primary key and the foreign key

The intercepted string is 15,151,152, 16 ', which can be considered an IP bar (although this does not refer to IP), And then we're going to intercept each comma before that part The following means: To get the characters of different index bits in

Three ways to connect to a database 1. General mode: $con =mysql_connect ($dbhostip, $username, $userpassword) or die ("Unable to connect to the mysql!"); $db = mysql_select_db ($dbdatabasename, $con); Executes the statement $qres

MYSQL noinstall-5.1.xx-win32 Configuration (original)1, decompression mysql-noinstall-5.1.xx-win32.zip to your favorite directory, such as: D:\php\mysql 2. There are five configuration information files in the root directory d:\php\mysql: My-small.

MySQL is installed on Windows and the default is run with system privileges, as shown in the following figure: System is a super administrator. It is not necessary to run any programs with this right. This article will show you how to run MySQL

Today, I received a call from a friend who said that the database was changed by others, and the problem of incorrect data appeared. After a long time, the data type has overflowed (the version of the problem is MySQL 5.1).　Later, through the friend