implement update_row to complete the generic CRUD operations for the DB. The proc_macros can now be removed

Author: hgzimmerman

backend/db/src/calls/mod.rs

@@ -49,7 +49,14 @@ use diesel::query_source::QuerySource;
 use diesel::query_dsl::filter_dsl::FilterDsl;
 use std::fmt::Debug;
 use crate::calls::user::NewUser;
+use diesel::query_builder::UpdateStatement;
+use diesel::helper_types::Update;
+use crate::calls::article::ArticleChangeset;
+use crate::Article;
 
+
+/// Generic function for getting a whole row from a given table.
+#[inline(always)]
 pub fn get_row<'a, Model, Table>(table: Table, uuid: Uuid, conn: &PgConnection) -> Result<Model, Error>
  where
  Table: FindDsl<Uuid>,
@@ -65,17 +72,13 @@ fn get_user(uuid: UserUuid,conn: &PgConnection) -> Result<User, Error> {
 }
 
 
+/// Generic function for deleting a row from a given table.
+#[inline(always)]
 pub fn delete_row<'a, Model, Tab>(table: Tab, uuid: Uuid, conn: &PgConnection) -> Result<Model, Error>
  where
 
  Tab: FindDsl<Uuid> + Table ,
  <Tab as FindDsl<Uuid>>::Output: IntoUpdateTarget,
- // For execute
-// <<<Tab as diesel::query_dsl::filter_dsl::FindDsl<uuid::Uuid>>::Output as diesel::associations::HasTable>::Table as diesel::QuerySource>::FromClause: QueryFragment<Pg>,
-// <<Tab as diesel::query_dsl::filter_dsl::FindDsl<uuid::Uuid>>::Output as diesel::query_builder::IntoUpdateTarget>::WhereClause: QueryId,
-// <<Tab as diesel::query_dsl::filter_dsl::FindDsl<uuid::Uuid>>::Output as diesel::associations::HasTable>::Table: QueryId,
-// <<Tab as diesel::query_dsl::filter_dsl::FindDsl<uuid::Uuid>>::Output as diesel::query_builder::IntoUpdateTarget>::WhereClause: QueryFragment<Pg>,
- // for get result
  Pg: HasSqlType<<<<<Tab as FindDsl<Uuid>>::Output as HasTable>::Table as Table>::AllColumns as Expression>::SqlType>,
  <<<Tab as FindDsl<Uuid>>::Output as HasTable>::Table as Table>::AllColumns: QueryId,
  <<<Tab as FindDsl<Uuid>>::Output as HasTable>::Table as Table>::AllColumns: QueryFragment<Pg>,
@@ -90,21 +93,26 @@ fn delete_user(uuid: UserUuid, conn: &PgConnection) -> Result<User, Error> {
 }
 
 
-//fn update_row<'a, Chg: 'a, Tab>(table: Tab, changeset: &Chg, conn: &PgConnection) -> ()
-//where
-// &'a Chg: AsChangeset<Target = Tab>,
-// Tab: QuerySource + Table + HasTable,
-//// Tab: FilterDsl,
-// &'a Chg: IntoUpdateTarget,
-// <<<Tab as HasTable>::Table as AsQuery>::Query as FilterDsl<Chg>>::Output: IntoUpdateTarget
-//// Tab as FilterDsl
-//// UpdateStatement<_>: LoadQuery<PgConnection, Model>
-//{
-// diesel::update(table)
-// .set(changeset);
-//}
+/// Generic function for updating a row for a given table with a given changeset.
+#[inline(always)]
+fn update_row<'a, Model, Chg, Tab>(table: Tab, changeset: Chg, conn: &PgConnection) -> Result<Model, Error>
+where
+ Chg: AsChangeset<Target=<Tab as HasTable>::Table>,
+ Tab: QuerySource + IntoUpdateTarget,
+ Update<Tab, Chg>: LoadQuery<PgConnection, Model>
+{
+ diesel::update(table)
+ .set(changeset)
+ .get_result::<Model>(conn)
+}
+
+fn update_article(changeset: ArticleChangeset, conn: &PgConnection) -> Result<Article, Error> {
+ update_row::<Article, ArticleChangeset,_>(schema::articles::table, changeset, conn)
+}
 
 
+/// Generic function for creating a row for a given table with a given "new" struct for that row type.
+#[inline(always)]
 fn create_row<Model, NewModel, Tab>(table: Tab, insert: NewModel, conn: &PgConnection) -> Result<Model, Error>
 where
  NewModel: Insertable<Tab>,
@@ -121,7 +129,6 @@ where
 }
 
 
-
 fn create_user(new_user: NewUser, conn: &PgConnection) -> Result<User, Error> {
  create_row::<User, NewUser,_>(schema::users::table, new_user, conn)
 }