[Ur] Minor question about simple Sql demo

[Adam Chlipala]

Every traditional HTML form submission creates a record of the values of 
all widgets from this form.  Even if the form has no widgets, you still 
get a record: the trivial empty record (or "unit" value).  The 'action' 
attribute of <submit> takes a function from the appropriate record 
type.  Thus, in your example with a no-widgets form, it is necessary to 
pass a function over the unit type, to stand for the empty widget-values 
data.

On 09/16/2015 11:10 AM, Stefan Scott wrote:
> My modified version (which now has two tables: a child table `Thing` 
> and a parent table `Color`) is here:
>
> https://github.com/StefanScott/UrWeb-demoSql-1
>
> This modified version compiles and runs correctly.
>
> ---
>
> Now I tried doing a minor modification.
>
> I noticed that the `delete` function takes two arguments:
>
>   delete id ()
>
> The second argument seemed unnecessary, so I tried removing it.
>
> However, removing the second argument gave a compile error: