fix: set collection id col to auto-incr and fix get_collection_id (mozilla-services#1929)

Inserting into collections in `get_or_create_collection_id` was failing.

The wrong column name was used in `get_collection_id`.  It's also been
converted to Diesel ORM calls.

Closes STOR-422

Author: chenba

syncstorage-postgres/migrations/2025-10-20-155711_create_schema/up.sql

@@ -39,7 +39,7 @@ CREATE INDEX bsos_expiry_idx ON bsos (
 
 -- collections table
 CREATE TABLE collections (
-    collection_id INTEGER PRIMARY KEY,
+    collection_id INTEGER GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
     name VARCHAR(32) NOT NULL UNIQUE
 );
 
@@ -87,4 +87,4 @@ CREATE TABLE batch_bsos (
         collection_id,
         batch_id
     ) ON DELETE CASCADE
-);
+);

syncstorage-postgres/src/db/db_impl.rs

@@ -5,8 +5,7 @@ use chrono::{NaiveDateTime, TimeDelta};
 use diesel::{
     delete,
     dsl::{count, max, sql},
-    sql_query,
-    sql_types::{BigInt, Integer, Nullable, Text},
+    sql_types::{BigInt, Integer, Nullable},
     ExpressionMethods, OptionalExtension, QueryDsl, SelectableHelper,
 };
 use diesel_async::{AsyncConnection, RunQueryDsl, TransactionManager};
@@ -23,7 +22,7 @@ use crate::{
     db::CollectionLock,
     orm_models::BsoChangeset,
     pool::Conn,
-    schema::{bsos, user_collections},
+    schema::{bsos, collections, user_collections},
     DbError, DbResult,
 };
 
@@ -513,17 +512,14 @@ impl Db for PgDb {
             return Ok(id);
         }
 
-        let id = sql_query(
-            "SELECT id
-               FROM collections
-              WHERE name = $1",
-        )
-        .bind::<Text, _>(name)
-        .get_result::<IdResult>(&mut self.conn)
-        .await
-        .optional()?
-        .ok_or_else(DbError::collection_not_found)?
-        .id;
+        let id = collections::table
+            .select(collections::collection_id)
+            .filter(collections::name.eq(name))
+            .first::<i32>(&mut self.conn)
+            .await
+            .optional()?
+            .ok_or_else(DbError::collection_not_found)?;
+
         if !self.session.in_write_transaction {
             self.coll_cache.put(id, name.to_owned())?;
         }
@@ -600,12 +596,6 @@ impl Db for PgDb {
     }
 }
 
-#[derive(Debug, QueryableByName)]
-struct IdResult {
-    #[diesel(sql_type = Integer)]
-    id: i32,
-}
-
 #[derive(Debug, Queryable, Selectable)]
 #[diesel(table_name = bsos)]
 pub struct GetBso {