Foreign key support is missing from text and file module

This is a great addition, and will allow contrib to implement filter manipulation more easily if it proves to be necessary. The concept of foreign key is SQL specific, but this information can be used regardless of the way the fields are actually stored.

See http://drupal.org/node/45111

Oops - wrong issue

#5: field_foreign_key.patch queued for re-testing.

+++ modules/field/field.crud.inc	2010-09-17 22:04:13 +0000
@@ -79,6 +79,13 @@
+ * - foreign keys (array)
+ *    An associative array of relations ('my_relation' => specification). Each
+ *    specification is an array containing the name of the referenced table
+ *    ('table'), and an array of column mappings ('columns'). Column mappings
+ *    are defined by key pairs ('source_column' => 'referenced_column').
+ *    Currently this has limited usefulness as you can not specify another
+ *    field as related, only existing data in SQL tables, like filter formats.

This doesn't explain it for me. What is the purpose? What is a column mapping? What is a source column and what is a referenced column? I think we can do a better job documenting this feature -- especially if it is perceived as 'critical'.

Then file fields need to be updated as well ? fid column is a FK to the file table.

#2: field_foreign_key.patch queued for re-testing.

+++ modules/field/field.crud.inc	2010-09-17 22:04:13 +0000
@@ -79,6 +79,13 @@
+ *    Currently this has limited usefulness as you can not specify another
+ *    field as related, only existing data in SQL tables, like filter formats.

This limitation could be easily resolved by squeezing a drupal_alter() into the process, no?

Powered by Dreditor.

Not in this issue, no.
#691932: Add hook_field_schema_alter()
#872146: Impossible to alter field_schema

+++ modules/field/field.crud.inc	2010-09-24 19:55:02 +0000
@@ -79,6 +79,13 @@
+ * - foreign keys (array)
+ *    An associative array of relations ('my_relation' => specification). Each
+ *    specification is an array containing the name of the referenced table
+ *    ('table'), and an array of column mappings ('columns'). Column mappings
+ *    are defined by key pairs ('source_column' => 'referenced_column').
+ *    Currently this has limited usefulness as you can not specify another
+ *    field as related, only existing data in SQL tables, like filter formats.

Still contains the phpDoc that Dries already rejected. That said, I think it is wrong to duplicate hook_schema() documentation in field.crud.inc. We should simply refer to hook_schema() here (which badly needs to be improved; separate issue), and if a dead-simple drupal_alter() really cannot be done within this patch, then we also keep that last sentence after referring to hook_schema().

+++ modules/field/modules/text/text.install	2010-09-24 19:55:02 +0000
@@ -56,5 +56,11 @@ function text_field_schema($field) {
+      $field['type'] . '_' . 'format' => array(

+++ modules/file/file.install	2010-09-24 19:56:42 +0000
@@ -35,6 +35,12 @@ function file_field_schema($field) {
+      'fid' => array(

Shouldn't the foreign key of File field also use the field type as prefix to prevent potential clashes? I.e., 'file_fid'?

Powered by Dreditor.

grml...

#26: field_foreign_key.patch queued for re-testing.

OK, committed to CVS HEAD. I'm still not 100% convinced about this but in the spirit of making progress, it seems best to move forward with this. We can nitpick about it in the Drupal 8 development cycle.

Head 2 Head issue is here: #935278: Update for foreign key support missing from text and file module

(Hopefully one of the last ones!)

Followup doc patch, to update the phpdoc and sample function body for hook_field_schema() accordingly.

I prefer: "foreign keys": (optional) An array of Schema API column defintions

A doc-only patch cannot introduce test fails. Looks like HEAD is broken...

@moshe : "An array of Schema API column definitions" ?
To me that sounds like array('type' => 'serial', 'unsigned' => TRUE, 'not null' => TRUE, ...)

The intent here is "what you would place in the 'foreign keys' entry in a regular hook_schema()".

+++ modules/field/field.api.php
@@ -219,7 +219,7 @@ function hook_field_info_alter(&$info) {
- *   - columns: An array of Schema API column specifications, keyed by column
+ *   - "columns": An array of Schema API column specifications, keyed by column

Without quotes is correct, so please revert. See http://drupal.org/node/1354 for details.

#34: hook_field_schema_FK_doc.patch queued for re-testing.

I thought that keys composed of two words (space, not underscore : foreign keys) needed to be enclosed in quotes. If that's not the case, then here it is without quotes.

OK, we are good.

Committed to CVS HEAD. Thanks.

Taxonomy fields were forgotten : #970016: taxonomy_field_schema lacks any foreign key support