kordophone-db: switch to diesel for more features

kordophone-db/src/schema.rs

@@ -0,0 +1,27 @@
+diesel::table! {
+    conversations (id) {
+        id -> Text,
+        unread_count -> BigInt,
+        display_name -> Nullable<Text>,
+        last_message_preview -> Nullable<Text>,
+        date -> Timestamp,
+    }
+}
+
+diesel::table! {
+    participants (id) {
+        id -> Integer,
+        display_name -> Text,
+    }
+}
+
+diesel::table! {
+    conversation_participants (conversation_id, participant_id) {
+        conversation_id -> Text,
+        participant_id -> Integer,
+    }
+}
+
+diesel::joinable!(conversation_participants -> conversations (conversation_id));
+diesel::joinable!(conversation_participants -> participants (participant_id));
+diesel::allow_tables_to_appear_in_same_query!(conversations, participants, conversation_participants);