Application of MySQL view to create a view
The application of MySQL view to create a view
View is also called a virtual table, including a set of records returned by executing a query . Views can simplify the method of obtaining data and implement abstract queries through aliases.
In order to simplify the query, in the actual project development process, you can usually create a view for a certain table in the database. Only the fields that developers care about are created in the view. Enter the username and password of the logged-in user in the input box respectively. After clicking the "Enter" button, if the user enters an incorrect username or password, an error prompt will be given. Otherwise, if the entered username and password are correct, a successful login will be prompted. .
Recommended related mysql video tutorials: "mysql tutorial"
Technical points
Creating views in MySQL can be achieved through the create view statement. The specific creation format is as follows:
$create [ or deplace] [algorithm={merge | temptable | undefined}] view view_name[( column_list)] as select_statement [with [cascaded | local] check option]algorithm={merge | temptable | undefined} attribute is used to optimize the execution of MySQL views. This attribute has 3 available set up. The following will introduce how to use these 3 settings.
merge: This parameter causes any clauses passed in when MySQL executes the view to be merged into the view's query definition.
temptable: If the data in the table below the view changes, these changes will be reflected immediately on the next pass through the table.
undefined: When the query result and the view result have a one-to-one correspondence, MySQL sets the algorithm to temptable.
view_name: The name of the new view.
select_statement: SQL query statement is used to limit the contents of the virtual table.
mysql view creation process
Since this example uses a view to create a virtual table, it should be created first under the "Command Prompt" view, you can create a view at the command prompt. The code to create the view is as follows:
create view chkadmin as select username, password from user
Create the view in the "Command Prompt" as follows:
After creating the view chkadmin, the view only contains There are two fields, username and password, which will bring great convenience to the password verification work.
Then we create the user input login interface, connect to the database, and determine whether the user clicked the "Enter" button. If so, verify the user identity through the view chkadmin. The process code is as follows:
<form method="post" action="3.php" name="form1">
用户名：<input type="text" name="username" ><br>
密 码：<input type="password" name="pwd"><br>
<input type="submit" name="Submit" value="进入">
<input type="submit" value="重置">
</form>
<?php
if($_POST['Submit']){
$name = $_POST['username'];
$password = $_POST['pwd'];
header("Content-Type:text/html; charset=utf-8");
$link = mysqli_connect("localhost", "root", "root");
$conn = mysqli_select_db($link, "php_cn");
$sql = ("select * from chkadmin where username='".$name."' and password = '".$password."'");
$result = mysqli_query($link, $sql);
$res = mysqli_fetch_array($result, MYSQLI_ASSOC);
if ($res==false){
echo "<script>alert('用户名或者密码输入错误');history.back();</script>";
exit();
}else{
echo "<br><p align='center'>登录成功！</p>";
}
}When we enter wrong information, as shown below:
When we enter correct information, as shown below:
Then we will introduce the MySQL creation view here. Have you guys mastered it? If you haven’t mastered it yet, you can read another article carefully. , in the next article we will continue to introduce the application of MySQL views. For details, please read "MySQL View Applications - Modifying Views"!
【Recommended related tutorials】
1.【MYSQL online free video tutorial】
2. Recommended related video courses : "Han Shunping's latest MySQL basic video tutorial in 2016"
The above is the detailed content of Application of MySQL view to create a view. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
MySQL: An Introduction to the World's Most Popular Database
Apr 12, 2025 am 12:18 AM
MySQL is an open source relational database management system, mainly used to store and retrieve data quickly and reliably. Its working principle includes client requests, query resolution, execution of queries and return results. Examples of usage include creating tables, inserting and querying data, and advanced features such as JOIN operations. Common errors involve SQL syntax, data types, and permissions, and optimization suggestions include the use of indexes, optimized queries, and partitioning of tables.
MySQL's Place: Databases and Programming
Apr 13, 2025 am 12:18 AM
MySQL's position in databases and programming is very important. It is an open source relational database management system that is widely used in various application scenarios. 1) MySQL provides efficient data storage, organization and retrieval functions, supporting Web, mobile and enterprise-level systems. 2) It uses a client-server architecture, supports multiple storage engines and index optimization. 3) Basic usages include creating tables and inserting data, and advanced usages involve multi-table JOINs and complex queries. 4) Frequently asked questions such as SQL syntax errors and performance issues can be debugged through the EXPLAIN command and slow query log. 5) Performance optimization methods include rational use of indexes, optimized query and use of caches. Best practices include using transactions and PreparedStatemen
Why Use MySQL? Benefits and Advantages
Apr 12, 2025 am 12:17 AM
MySQL is chosen for its performance, reliability, ease of use, and community support. 1.MySQL provides efficient data storage and retrieval functions, supporting multiple data types and advanced query operations. 2. Adopt client-server architecture and multiple storage engines to support transaction and query optimization. 3. Easy to use, supports a variety of operating systems and programming languages. 4. Have strong community support and provide rich resources and solutions.
How to connect to the database of apache
Apr 13, 2025 pm 01:03 PM
Apache connects to a database requires the following steps: Install the database driver. Configure the web.xml file to create a connection pool. Create a JDBC data source and specify the connection settings. Use the JDBC API to access the database from Java code, including getting connections, creating statements, binding parameters, executing queries or updates, and processing results.
How to start mysql by docker
Apr 15, 2025 pm 12:09 PM
The process of starting MySQL in Docker consists of the following steps: Pull the MySQL image to create and start the container, set the root user password, and map the port verification connection Create the database and the user grants all permissions to the database
MySQL's Role: Databases in Web Applications
Apr 17, 2025 am 12:23 AM
The main role of MySQL in web applications is to store and manage data. 1.MySQL efficiently processes user information, product catalogs, transaction records and other data. 2. Through SQL query, developers can extract information from the database to generate dynamic content. 3.MySQL works based on the client-server model to ensure acceptable query speed.
Laravel Introduction Example
Apr 18, 2025 pm 12:45 PM
Laravel is a PHP framework for easy building of web applications. It provides a range of powerful features including: Installation: Install the Laravel CLI globally with Composer and create applications in the project directory. Routing: Define the relationship between the URL and the handler in routes/web.php. View: Create a view in resources/views to render the application's interface. Database Integration: Provides out-of-the-box integration with databases such as MySQL and uses migration to create and modify tables. Model and Controller: The model represents the database entity and the controller processes HTTP requests.
How to install mysql in centos7
Apr 14, 2025 pm 08:30 PM
The key to installing MySQL elegantly is to add the official MySQL repository. The specific steps are as follows: Download the MySQL official GPG key to prevent phishing attacks. Add MySQL repository file: rpm -Uvh https://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm Update yum repository cache: yum update installation MySQL: yum install mysql-server startup MySQL service: systemctl start mysqld set up booting
