What is MIME type "application/x-mysql-db"?

A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.

application/x-mysql-db is a MIME type that identifies files storing MySQL table definitions. These files hold the structure of a database table, such as field types, indexes, and other metadata. They do not contain actual table data.

Files using this MIME type follow the MySQL Table Definition Format found in the file FRM.

Key facts and use cases:

Database Schema Storage: It marks files that contain table structure details used by MySQL.
System Integration: Software tools and database utilities use it to recognize and process table definitions.
Backup and Migration: The format can be involved in backing up and transferring database schemata.

This MIME type, with its "x-" prefix, signals a non-standard use case tailored to MySQL environments. For more detailed information about the file format, explore external resources such as this reference.

Associated file extensions

.frm

Usage Examples

HTTP Header

When serving content with this MIME type, set the Content-Type header:


    Content-Type: application/x-mysql-db

HTML

In HTML, you can specify the MIME type in various elements:


    <a href="file.dat" type="application/x-mysql-db">Download file</a>

Server-side (Node.js)

Setting the Content-Type header in Node.js:


    const http = require('http');    
    
    http.createServer((req, res) => {    
      res.setHeader('Content-Type', 'application/x-mysql-db');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.frm

FAQs

What type of file is identified by application/x-mysql-db?

This MIME type specifically identifies MySQL table definition files, which typically use the .frm extension. These files store the metadata and structure of a database table (such as column names and types) but do not contain the actual data rows.

How do I open or view a file with the application/x-mysql-db type?

Because these are binary files used internally by the MySQL server, you cannot open them with a standard text editor. To view the table structure contained in a FRM file, you should use the MySQL command line or a database management tool like phpMyAdmin or MySQL Workbench.

Should I configure my web server to serve application/x-mysql-db files?

Generally, no. You should configure servers like Apache or Nginx to block access to these files for security reasons. Exposing .frm files allows attackers to analyze your database structure, which can aid in SQL injection attacks.

What is the difference between application/x-mysql-db and application/sql?

application/sql is used for text-based SQL script files (like .sql) that contain readable queries and commands. In contrast, application/x-mysql-db refers to the binary format used by the database engine itself to store schema definitions on the disk.

How do I add this MIME type to Apache if needed for internal transfers?

If you specifically need to serve these files within a protected internal network, add AddType application/x-mysql-db .frm to your .htaccess or config file. Ensure strict authentication is in place, as these files reveal sensitive architecture details.

Why does this MIME type start with "x-"?

The x- prefix indicates that application/x-mysql-db is a non-standard or experimental type not officially registered with the IANA. It was adopted by the community and MySQL tools to specifically label proprietary table definition files.

General FAQ

What is a MIME type?

A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.

MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.

MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.

How do I find the MIME type for a file?

You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.

Why are multiple MIME types listed for one extension?

Different applications and historical conventions may use alternative MIME identifiers for the same kind of file. Showing them all helps ensure compatibility across systems.