使用grocery-crud关联id_ab失败，需提取Subname与Expire

Hey there, let's figure out why your Grocery CRUD relation isn't working and get you the Subname and Expire fields you need!

What's Going Wrong #

Looking at your code and table structure, a few issues are likely causing the relation to fail:

• Incorrect relation logic: The set_relation method expects the first parameter to be the foreign key in your main table, but your setup has lista_ab.id_ab as the primary key, and lista_ab_term.id_ab as the foreign key linking back to it. Your current call doesn't align with this relationship properly.
• Missing primary keys: Neither of your tables has a primary key defined in the CREATE statements. Grocery CRUD relies on primary keys to handle relations correctly.
• Unspecified display columns: You haven't told Grocery CRUD which fields to show, so even if the relation worked, you wouldn't see Subname and Expire by default.

Step-by-Step Fix #

1. Add Primary Keys to Your Tables #

First, let's fix the database structure by adding primary keys (this is critical for Grocery CRUD to function):

ALTER TABLE `lista_ab` ADD PRIMARY KEY (`id_ab`);
ALTER TABLE `lista_ab_term` ADD PRIMARY KEY (`ID`);

2. Update Your Grocery CRUD Code #

Adjust your code to correctly define the relation and specify the fields you want to extract:

$crud->set_table('lista_ab');
// Link the main table's id_ab to the related table's id_ab, and display the Expire field
$crud->set_relation('id_ab', 'lista_ab_term', 'Expire');
// Explicitly set the columns you want to show: Subname from lista_ab, Expire from lista_ab_term
$crud->columns('Subname', 'Expire');

If you're working with a one-to-many relationship (one lista_ab entry has multiple lista_ab_term entries), you might need to use set_relation_n_n or adjust how you fetch the data, but for a one-to-one match, the above code should work perfectly.

If you also want these fields to appear in the add/edit forms, add this line:

$crud->fields('Subname', 'Expire');

Quick Checks to Verify #

• Make sure there are matching id_ab values in both tables (the relation only works when the values align).
• Double-check that you're using a recent version of Grocery CRUD to avoid any outdated bugs.

内容的提问来源于stack exchange，提问作者Dobi Caps