Home Database Mysql Tutorial 关于 Access 数据库中的数据类型与 Access 项目中的数据类型的不

关于 Access 数据库中的数据类型与 Access 项目中的数据类型的不

Jun 07, 2016 pm 03:38 PM
access about data database type project

Microsoft Access 提供两种字段 数据 类型 (字段 数据 类型 :决定可以存储哪种 数据 的字段特征。例如, 数据 类型 为文本的字段可以存储由文本或数字字符组成的 数据 ,而数字字段只能存储数值 数据 。) 以存储文本或数字,或两者的组合:文本和备注。

Microsoft Access 提供两种字段数据类型 (字段数据类型:决定可以存储哪种数据的字段特征。例如,数据类型为“文本”的字段可以存储由文本或数字字符组成的数据,而“数字”字段只能存储数值数据。)以存储文本或数字,或两者的组合:“文本”和“备注”。

使用“文本”数据类型存储如名称、地址和任何不需计算的数字,如电话号码、部件编号或者邮政编码。“文本”字段能存储最多 255 个字符,但默认字段大小是 50 个字符。“字段大小”属性控制可以输入“文本”字段的最大字符个数。

如果需要存储超过 255 个字符,应使用“备注”数据类型。“备注”最多可以存储 65,536 个字符。如果要存储带格式文本或长文档,可以创建 OLE 对象字段代替“备注”字段。

“文本”和“备注”数据类型存储输入到一个字段中的值;不存储字段中没用的部分的空白字符。

可以对“文本”或者“备注”字段进行分组和排序,但 Access 只使用“备注”字段的前 255 个字符进行分组和排序。

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Hot Topics

Java Tutorial
1655
14
PHP Tutorial
1253
29
C# Tutorial
1227
24
How to configure zend for apache How to configure zend for apache Apr 13, 2025 pm 12:57 PM

How to configure Zend in Apache? The steps to configure Zend Framework in an Apache Web Server are as follows: Install Zend Framework and extract it into the Web Server directory. Create a .htaccess file. Create the Zend application directory and add the index.php file. Configure the Zend application (application.ini). Restart the Apache Web server.

Oracle's Role in the Business World Oracle's Role in the Business World Apr 23, 2025 am 12:01 AM

Oracle is not only a database company, but also a leader in cloud computing and ERP systems. 1. Oracle provides comprehensive solutions from database to cloud services and ERP systems. 2. OracleCloud challenges AWS and Azure, providing IaaS, PaaS and SaaS services. 3. Oracle's ERP systems such as E-BusinessSuite and FusionApplications help enterprises optimize operations.

MySQL vs. Other Databases: Comparing the Options MySQL vs. Other Databases: Comparing the Options Apr 15, 2025 am 12:08 AM

MySQL is suitable for web applications and content management systems and is popular for its open source, high performance and ease of use. 1) Compared with PostgreSQL, MySQL performs better in simple queries and high concurrent read operations. 2) Compared with Oracle, MySQL is more popular among small and medium-sized enterprises because of its open source and low cost. 3) Compared with Microsoft SQL Server, MySQL is more suitable for cross-platform applications. 4) Unlike MongoDB, MySQL is more suitable for structured data and transaction processing.

Using Dicr/Yii2-Google to integrate Google API in YII2 Using Dicr/Yii2-Google to integrate Google API in YII2 Apr 18, 2025 am 11:54 AM

VprocesserazrabotkiveB-enclosed, Мнепришлостольностьсясзадачейтерациигооглапидляпапакробоглесхетсigootrive. LEAVALLYSUMBALLANCEFRIABLANCEFAUMDOPTOMATIFICATION, ČtookazaLovnetakProsto, Kakaožidal.Posenesko

What is apache server? What is apache server for? What is apache server? What is apache server for? Apr 13, 2025 am 11:57 AM

Apache server is a powerful web server software that acts as a bridge between browsers and website servers. 1. It handles HTTP requests and returns web page content based on requests; 2. Modular design allows extended functions, such as support for SSL encryption and dynamic web pages; 3. Configuration files (such as virtual host configurations) need to be carefully set to avoid security vulnerabilities, and optimize performance parameters, such as thread count and timeout time, in order to build high-performance and secure web applications.

Nginx performance monitoring and troubleshooting tools Nginx performance monitoring and troubleshooting tools Apr 13, 2025 pm 10:00 PM

Nginx performance monitoring and troubleshooting are mainly carried out through the following steps: 1. Use nginx-V to view version information, and enable the stub_status module to monitor the number of active connections, requests and cache hit rate; 2. Use top command to monitor system resource occupation, iostat and vmstat monitor disk I/O and memory usage respectively; 3. Use tcpdump to capture packets to analyze network traffic and troubleshoot network connection problems; 4. Properly configure the number of worker processes to avoid insufficient concurrent processing capabilities or excessive process context switching overhead; 5. Correctly configure Nginx cache to avoid improper cache size settings; 6. By analyzing Nginx logs, such as using awk and grep commands or ELK

MySQL: Structured Data and Relational Databases MySQL: Structured Data and Relational Databases Apr 18, 2025 am 12:22 AM

MySQL efficiently manages structured data through table structure and SQL query, and implements inter-table relationships through foreign keys. 1. Define the data format and type when creating a table. 2. Use foreign keys to establish relationships between tables. 3. Improve performance through indexing and query optimization. 4. Regularly backup and monitor databases to ensure data security and performance optimization.

How to identify malicious access in Debian Apache logs How to identify malicious access in Debian Apache logs Apr 13, 2025 am 07:30 AM

Effective monitoring and defense against malicious website access is crucial to the Apache server on the Debian system. Apache access logs are the key source of information to identify such threats. This article will guide you on how to analyze logs and take defensive measures. The Apache access log that identifies malicious access behaviors Debian systems is usually located in /var/log/apache2/access.log. You can analyze the logs in a variety of ways: Log file location confirmation: First, please confirm the exact location of your Apache access log, which may vary slightly depending on the system configuration. Command line tool analysis: Use grep command to search for specific patterns, such as grep "404"

See all articles