What is the use case for this? about custom_field_sql HOT 3 CLOSED

Here is example - concatenation subject and value of one custom field as caption in sql_field:

select subject ||coalesce(c1.value,'') from issues
LEFT JOIN custom_values c1 ON c1.customized_id=issues.id AND c1.custom_field_id=24
where tracker_id = 6 and status_id = 2

for beginning:
select subject from issues

or

select name from issue_statuses

from custom_field_sql.

For sure I'll have a play with this, opens up some interesting possibilities. Nice work!

from custom_field_sql.

SQL field
With the simple SQL field, you can run a query that will result in a drop-down menu which is shown when that custom field is edited (e.g. project->configure). This is useful to confine the user input to select one value out of an already available dataset somewhere in the Redmine database (not an external database).

SQL seach field
Unfortunately, I really don't understand how the SQL search field works.
What I've got so far:

• In your query, you can insert one or me question marks (?) as placeholders for parameters
• In the parameter section, every line defines one parameter
• The line always starts with p0=, p1=, pN=...)
• In every line, a javascript command is assigned to the parameter
• We can use $(...) to get a DOM object by HTML id thanks to JQuery (short for: document.getElementById(...) )
• By the DOM id we can get access to the content of other custom fields in the editing dialog, e.g. $('#issue_custom_field_values_31').val()
• The DOM id can be retrieved in Firefox by right-clicking on a custom field and then choose to inspect / untersuchen

But here it ends... When selecting a value in one of the other custom fields (id=31), the search is not carried out. Also when I type something in the SQL search field it just acts as a normal string field.
What is the purpose of that search field and what do I do wrong perhaps?

from custom_field_sql.