数据库交互的几个简单的对象
以前曾经写过几篇关于.net对SQL SERVER编程中用到的几个对象，发现理解的不是很深刻，今天在这里在总结一下。 为何还会总结呢？ 因为试想无论是做WEB开发还是桌面应用程序，都离不开与数据库打交道（增、删、改、查）。无非就是这些操作，变化的只是前段页面
以前曾经写过几篇关于.net对SQL SERVER编程中用到的几个对象，发现理解的不是很深刻，今天在这里在总结一下。
为何还会总结呢？
因为试想无论是做WEB开发还是桌面应用程序，都离不开与数据库打交道（增、删、改、查）。无非就是这些操作，变化的只是前段页面，后台与数据库的交互是始终不变的。
无论是B/S还是所谓的C/S后台都是一回事，所以只要把后台数据库交互部分设置好了，工程就完成了一多半了。
常用对象
SqlConnection：表示一个到 SQL Server 数据库的打开的连接。 此类不能被继承。
ConnectionState：描述与数据源的连接的当前状态。
SqlCommand：表示要对 SQL Server 数据库执行的一个 Transact-SQL 语句或存储过程。 此类不能被继承。
SqlParameter：表示 SqlCommand 的参数。
SqlDataReader：提供一种从数据库读取行的只进流方式。
DataSet：表示一个存放于内存中的数据缓存。
SqlDataAdapter：表示用于填充 DataSet 和更新 SQL Server 数据库的一组数据命令和一个数据库连接。
这么多对象，如何来理解呢？看下面一副图片。
我们把上述的部分划分为两个部分来理解，就简单易懂了。
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
1664
14
1423
52
1317
25
1268
29
1244
24
iOS 18 adds a new 'Recovered' album function to retrieve lost or damaged photos
Jul 18, 2024 am 05:48 AM
Apple's latest releases of iOS18, iPadOS18 and macOS Sequoia systems have added an important feature to the Photos application, designed to help users easily recover photos and videos lost or damaged due to various reasons. The new feature introduces an album called "Recovered" in the Tools section of the Photos app that will automatically appear when a user has pictures or videos on their device that are not part of their photo library. The emergence of the "Recovered" album provides a solution for photos and videos lost due to database corruption, the camera application not saving to the photo library correctly, or a third-party application managing the photo library. Users only need a few simple steps
Detailed tutorial on establishing a database connection using MySQLi in PHP
Jun 04, 2024 pm 01:42 PM
How to use MySQLi to establish a database connection in PHP: Include MySQLi extension (require_once) Create connection function (functionconnect_to_db) Call connection function ($conn=connect_to_db()) Execute query ($result=$conn->query()) Close connection ( $conn->close())
How to convert MySQL query result array to object?
Apr 29, 2024 pm 01:09 PM
Here's how to convert a MySQL query result array into an object: Create an empty object array. Loop through the resulting array and create a new object for each row. Use a foreach loop to assign the key-value pairs of each row to the corresponding properties of the new object. Adds a new object to the object array. Close the database connection.
How to handle database connection errors in PHP
Jun 05, 2024 pm 02:16 PM
To handle database connection errors in PHP, you can use the following steps: Use mysqli_connect_errno() to obtain the error code. Use mysqli_connect_error() to get the error message. By capturing and logging these error messages, database connection issues can be easily identified and resolved, ensuring the smooth running of your application.
How to use database callback functions in Golang?
Jun 03, 2024 pm 02:20 PM
Using the database callback function in Golang can achieve: executing custom code after the specified database operation is completed. Add custom behavior through separate functions without writing additional code. Callback functions are available for insert, update, delete, and query operations. You must use the sql.Exec, sql.QueryRow, or sql.Query function to use the callback function.
How to save JSON data to database in Golang?
Jun 06, 2024 am 11:24 AM
JSON data can be saved into a MySQL database by using the gjson library or the json.Unmarshal function. The gjson library provides convenience methods to parse JSON fields, and the json.Unmarshal function requires a target type pointer to unmarshal JSON data. Both methods require preparing SQL statements and performing insert operations to persist the data into the database.
What is the difference between arrays and objects in PHP?
Apr 29, 2024 pm 02:39 PM
In PHP, an array is an ordered sequence, and elements are accessed by index; an object is an entity with properties and methods, created through the new keyword. Array access is via index, object access is via properties/methods. Array values are passed and object references are passed.
How to connect to remote database using Golang?
Jun 01, 2024 pm 08:31 PM
Through the Go standard library database/sql package, you can connect to remote databases such as MySQL, PostgreSQL or SQLite: create a connection string containing database connection information. Use the sql.Open() function to open a database connection. Perform database operations such as SQL queries and insert operations. Use defer to close the database connection to release resources.
