MySQL

SQL is an ANSI standard computer language used to access and operate database systems. SQL statements are used to retrieve and update data in the database. SQL can work with database programs, such as MySQL, MS Access, DB2, Informix, ms SQL Server,

I was shocked to see this name... Isn't SQL expected to quickly query and obtain results? How can this concept be implemented. I asked a buddy, who thought it was a man query: multiple queries at the same time. So Google came up with the

How to increase the number of connections to the MySQL database. After the MYSQL database is installed, the default number of connections is 100. The number of connections to forums or websites with a slightly higher traffic is insufficient, so how

Mysql cache function analysis: 1. The key Generation Principle of the mysql cache function is to generate a unique key based on the select statement according to certain hash rules. The select result generates a value, that is, key => value.

In MySQL, inserting a record is very simple, but in some special applications, before inserting a record, you need to check whether the record already exists. The insert operation is performed only when the record does not exist, this article

How can I set the installed phpmyadmin to automatic login! (1) Find config in the root directory. inc. php (root directory) or config. default. php (root directory) And then: libraries \ config. default. php (Friendly reminder: Because different

This article introduces five common MySQL parameters, including connection, query cache, temporary table, session memory, and slow query log. (1) Connection The connection usually comes from the Web server. The following lists some

Program = Data + algorithm. This is the simplest definition of a program. Without a doubt, a program will inevitably store a large amount of data. for data storage, most developers should immediately think of the database, however, not all data is

A simple table tells you some query skills and index creation knowledge points. In a database table, you can create an index on fields to greatly improve the query speed. Suppose we have created a mytable table:Create table mytable (Id int not

Friends who are developing, especially those who have contact with mysql, may encounter mysql Server slow down as a result of time. Of course, I am referring to a large data volume of millions and tens of millions, it's not dozens of times. Let's

The usage of tinyint, smallint, int, and bigint types in mysql is different: In MySQL, the value range of Tinyint is-128 to 127. The unsigned range is 0 to 255 (see the official MySQL 5.1 reference manual.) Tinyint occupies 1 byte of storage space,

In web projects, the entire site search problem is often encountered, that is, the customer wants to enter a word in the search box of the website, then, the page containing the word will appear in the search results on the entire website. Since a

MySQL queries table indexes in two command forms: Mysql> SHOW index FROM 'tblname '; Or: Mysql> SHOW keys FROM 'tblname '; The result obtained by running the preceding command is as follows. The meaning of each column in the result is described

When developing large-traffic access-level web application development projects, we have to constantly inspect and optimize various functions in the application to Prevent the application from being suspended at critical times. The authors will give

The length function in mysql is a built-in function used to obtain the string length. The usage example is as follows: (1) view the length of a string (such as the website) Select length ('www .phpernote.com '); (2) query the top 10 articles in

During development and testing, applications often encounter situations where table replication is required, for example, copying some or all of the fields of Table 1 data to table 2, this is the time when select into or insert into select plays an

The following is a summary of some common commands used in MySQL. 1. Start and exit 1. Go to MySQL: Start MySQL Command Line Client (MySQL DOS Interface) and enter the password for installation. The prompt is: mysql> 2. exit MySQL: quit or exit Ii.

1. To optimize the query, try to avoid full table scanning. First, consider creating an index on the columns involved in where and order. 2. Try to avoid null value determination on the field in the where clause. Otherwise, the engine will discard

Sometimes we need to know the space occupied by a table in the MySQL database because of work needs. How can this problem be solved? In fact, it is very simple. Have you noticed that all databases will come with a information_schema database that

Indexes increase data access speeds. However, creating indexes also increases the processing time for insert, update, and delete operations and increases the storage space of physical disks. Therefore, whether to add an index to the data table or