dede field name是什么标签？

Of course! The dede_field name is a core concept in the DedeCMS (织梦内容管理系统) database. It's the central table that stores the custom fields for your website's content.

Let's break it down in detail.

What is dede_field?

In simple terms, dede_field is a lookup table that defines all the extra, user-defined fields you can add to a specific content model (also called an "arctype" or channel).

Think of it this way:

• dede_archives: This table holds the standard, fixed information for every article, like its title, author, publishing date, and the main body content.
• dede_field: This table holds the definitions for additional information you might want to capture. For example, if you're running a product review site, you could add custom fields like "Product Rating," "Price," or "Release Date." The dede_field table stores the names and properties of these custom fields.

Every time you create a new content model in the DedeCMS backend (e.g., "Products," "Downloads," "Staff Members"), DedeCMS creates a corresponding table in the database (like dede_addonproducts) to store the data for that specific model. The dede_field table tells DedeCMS what fields to create in that new table.

Structure of the dede_field Table

Here are the most important columns in the dede_field table and what they mean:

How It Works: A Practical Example

Let's imagine you want to create a content model for "Book Reviews".

Step 1: Create the Content Model in DedeCMS Backend

1. Go to 核心 -> 内容模型管理 -> 增加一个内容模型.
2. Fill in the details:
   • 模型名称: Book Reviews
   • 模型表: dede_addonbook (DedeCMS will suggest this)
3. Click "Submit".

Step 2: Add Custom Fields

1. Go to 内容模型管理 -> 管理字段.
2. You will see a dropdown for your new model ("Book Reviews"). Select it.
3. Now, add the fields you need. For each field, you'll define its properties:
   • Field 1: "Book Author"
     • 字段名: book_author
     • : Book Author
     • 字段类型: text
   • Field 2: "My Rating"
     • 字段名: my_rating
     • : My Rating (out of 5)
     • 字段类型: radio
     • 字段参数: 5:Five Stars,4:Four Stars,3:Three Stars,2:Two Stars,1:One Star
   • Field 3: "Book Cover Image"
     • 字段名: book_cover
     • : Book Cover Image
     • 字段类型: img

What Happens in the Database?

1. A new table named dede_addonbook is created. It will have the standard columns plus the new ones you defined: book_author, my_rating, and book_cover.
2. Three new rows are added to the dede_field table:
   • One for book_author.
   • One for my_rating.
   • One for book_cover.
   • The fieldset column for all these rows will be 'book' (or whatever you named your model).

When you now go to write a new "Book Review," DedeCMS checks the dede_field table for all fields where fieldset = 'book' and displays them on the editing form based on their dtype and titlename.

Why is Understanding dede_field Important?

1. Templating (Frontend Development): To display the content of a custom field in your template files (.htm), you use the field function. For example, to display the book author, you would use:

   {dede:field name='book_author'/}

2. PHP Development: If you are writing a custom PHP script to get article data, you'll need to know the field names to query them from the corresponding addon table (e.g., dede_addonbook).

3. Debugging: If a custom field is not showing up on the frontend or backend, the problem is often in the dede_field table. You might find:

   • The fieldset name is incorrect.
   • The ifshow value is 0.
   • The titlename is empty.

4. Data Migration: When moving a DedeCMS site, you must not only back up the data tables (dede_archives, dede_addon*) but also the dede_field table, otherwise, you will lose all your custom field definitions.