new schema which ultimately simplfies things for us

server/migrations/2020-02-04-083657_invites/up.sql

@@ -1,15 +1,12 @@
--- @id : id of the invite
-
--- @expires : unix timestamp of when that invite expries
--- can be set to null which means it never expires
+-- @id : id of the invite which is also its kill date
 
 -- @uses : can be null which means it doesn't have a use limit
 
--- @max_uses : if this is null uses only ever incremented but we don't care for destroying on that parameter
+-- @expires: boolean that tells wether the key expires or not
+
 CREATE TABLE IF NOT EXISTS `invites` (
-	`id` bigint UNSIGNED NOT NULL,
-	`expires` bigint,
-	`uses` integer, 
-	`max_uses` integer,
+	`id` BIGINT UNIQUE NOT NULL,
+	`uses` BIGINT, 
+	`expires` BOOLEAN NOT NULL,
 	PRIMARY KEY( `id` )
 );