In the field editor "Default Value" is what appears in the field when you create a new record in the CMS.  The user can see this value and change it if needed.

For MySQL, you can set a custom column type at the bottom to something like "INT DEFAULT 555" (without quotes), and if any code attempts to insert a row without specifying a value for that column, it will be set to the specified value (e.g. 555).

Hope that helps!

Yea, the CMSB "unique" value validation runs at the application level. 

I think we initially did it that way many years ago because virtual hosts didn't always grant INDEX privileges.  You can actually see under: Admin > General > Server Info > Database Server > Privileges we're displaying the INDEX status to indicate if it's available on the server.  That said, it's on our list to implement this feature as well.  

You can either manually add a unique index yourself through the Developer Console plugin, or here's some code you can add to ensure it's always present (such as before an import operation):

// Ensure accounts.username has a UNIQUE INDEX on it
$hasUniqueIndex = DB::query("SHOW INDEX FROM ::accounts WHERE Non_unique = ?", 0)->pluck('Column_name')->contains('username');
if (!$hasUniqueIndex) {
    DB::query("ALTER TABLE ::accounts ADD UNIQUE INDEX (username)");
}

You'll then be able to see that index under: CMS Setup > Database > User Accounts] > Source
Or: admin.php?menu=database&action=editTable&tableName=accounts#tab_mysqlSource

ZenDB does not appear to support the REPLACE command, which can be used as an alternative to INSERT. Right now, we need to do a get or query, then insert for each record. 

Try using the DB::query() method as I've done above for executing any custom queries.

Also, would views and stored procedures be possible?

Yes, but we don't have the CMSB logic to store and recreate them in the CMS schema files.  So when we need to do things like that we often add application code to detect and recreate them, or maybe a plugin to do it once, as we often need to move code between servers and need everything to be portable.  I usually use the Developer Console Plugin for quick queries.

Let me know any questions.

ZenDB does not appear to support the REPLACE command, which can be used as an alternative to INSERT. Right now, we need to do a get or query, then insert for each record. 

Also would views and stored procedurs be possible?