diff --git a/koucha/src/db.rs b/koucha/src/db.rs
index 6914cfa..d103e86 100644
--- a/koucha/src/db.rs
+++ b/koucha/src/db.rs
@@ -12,11 +12,10 @@ mod item;
 pub use item::Item;
 
 macro_rules! define_id {
-    ($name:ident) => {
-      #[derive(PartialEq, Debug, Copy, Clone)]
-      pub struct $name(i64);
-      impl From<$name> for i64 { fn from(id: $name) -> Self { id.0 } }
-    };
+  ($name:ident) => {
+    #[derive(PartialEq, Debug, Copy, Clone)]
+    pub struct $name(i64);
+  };
 }
 
 define_id!(UserId);
diff --git a/koucha/src/db/channel.rs b/koucha/src/db/channel.rs
index 6df59fb..d7dfca9 100644
--- a/koucha/src/db/channel.rs
+++ b/koucha/src/db/channel.rs
@@ -245,10 +245,7 @@ mod tests {
     let channel1 = Channel::get_or_create(pool, url_feed.clone()).await.unwrap();
     let channel2 = Channel::get_or_create(pool, url_feed).await.unwrap();
 
-    assert_eq!(
-      i64::from(channel1.id()),
-      i64::from(channel2.id())
-    );
+    assert_eq!(channel1.id(), channel2.id());
   }
 
   #[tokio::test]
diff --git a/koucha/src/db/feed.rs b/koucha/src/db/feed.rs
index a769b1b..f3a8559 100644
--- a/koucha/src/db/feed.rs
+++ b/koucha/src/db/feed.rs
@@ -49,13 +49,12 @@ impl Feed {
   pub async fn create(
     pool: &AdapterPool, user_id: UserId, title: &str
   ) -> Result<Self> {
-    let int_id = i64::from(user_id);
     let new_feed = sqlx::query_as!(
       UnparsedFeed,
       "INSERT INTO feeds (user_id, title) 
        VALUES (?, ?)
        RETURNING id as `id!`, title",
-      int_id, title
+      user_id.0, title
     ).fetch_one(&pool.0).await?.parse();
 
     new_feed
@@ -75,11 +74,10 @@ impl Feed {
   pub async fn add_channel(
     &self, pool: &AdapterPool, channel_id: ChannelId
   ) -> Result<()> {
-    let int_channel_id = i64::from(channel_id);
     sqlx::query!(
       "INSERT INTO feed_channels (feed_id, channel_id)
        VALUES (?, ?)",
-      self.id.0, int_channel_id
+      self.id.0, channel_id.0
     ).execute(&pool.0).await?;
 
     Ok(())
diff --git a/koucha/src/db/feed_channel.rs b/koucha/src/db/feed_channel.rs
index f8a3870..27e39f9 100644
--- a/koucha/src/db/feed_channel.rs
+++ b/koucha/src/db/feed_channel.rs
@@ -60,15 +60,14 @@ impl FeedChannel {
   async fn add_item_at(
     &self, pool: &AdapterPool, item: &Item, add_at: DateTime<Utc>
   ) -> Result<()> {
-    let int_item_id = i64::from(item.id());
-    let int_feed_id = i64::from(self.feed_id);
+    let int_item_id = item.id().0;
     let int_initial_score = i64::from(self.initial_score);
     let string_last_updated = add_at.to_rfc2822();
 
     sqlx::query!(
       "INSERT OR IGNORE INTO feed_items (feed_id, item_id, score, last_updated)
        VALUES (?, ?, ?, ?)",
-      int_feed_id, int_item_id, int_initial_score, string_last_updated
+      self.feed_id.0, int_item_id, int_initial_score, string_last_updated
     ).execute(&pool.0).await?;
     Ok(())
   }
diff --git a/koucha/src/db/item.rs b/koucha/src/db/item.rs
index cb25331..a910a14 100644
--- a/koucha/src/db/item.rs
+++ b/koucha/src/db/item.rs
@@ -58,7 +58,6 @@ impl Item {
   pub async fn get_or_create(
     pool: &AdapterPool, from_channel: ChannelId, guid: &str
   ) -> Result<Self> {
-    let int_channel_id = i64::from(from_channel);
 
     let item = sqlx::query_as!(
       UnparsedItem,
@@ -67,7 +66,7 @@ impl Item {
        ON CONFLICT(channel_id, guid) DO UPDATE SET channel_id = channel_id
        RETURNING id as `id!`, channel_id, fetched_at, title, description,
          content",
-      int_channel_id, guid
+      from_channel.0, guid
     ).fetch_one(&pool.0).await?.parse();
 
     item