SQL Custom Field Default Value and No Value when field is optional Topic is solved

[Amongthegums]

Following the advice in the docs (https://docs.joomla.org/SQL_form_field_type) I have hit a brick wall trying to assign a default value. It seems no matter what I enter into the default field I get a fatal error on save.

My SQL follows the format "SELECT id AS value, name AS text FROM some_table"

A valid value, for example 1, is entered as 1 into the default field and I hit save to get Invalid Default Value Error!(?)

What is the correct format for entering the default value?

Second, is there any way to force a NULL or blank value for optional SQL fields, i.e. no selection.

Thanks in advance.

[Amongthegums]

For what it's worth I fudged it with SQL

SELECT 0 AS value, '- Select a delegate -' AS text
UNION
SELECT #_users.id AS value, #_users.name AS text
FROM
#_users

This way value - "Select a delegate" is the default choice on new records. That'll work for me.