add get_rows, which will return all rows of a given table

Author: hgzimmerman

backend/db/src/calls/mod.rs

@@ -53,6 +53,14 @@ use diesel::query_builder::UpdateStatement;
 use diesel::helper_types::Update;
 use crate::calls::article::ArticleChangeset;
 use crate::Article;
+use diesel::select;
+use diesel::expression::exists::exists;
+use diesel::query_builder::SelectQuery;
+use diesel::expression::subselect::ValidSubselect;
+use diesel::query_builder::SelectStatement;
+use diesel::expression::exists::Exists;
+use diesel::helper_types::Select;
+use diesel::query_dsl::select_dsl::SelectDsl;
 
 
 /// Generic function for getting a whole row from a given table.
@@ -71,6 +79,15 @@ fn get_user(uuid: UserUuid,conn: &PgConnection) -> Result<User, Error> {
  get_row::<User,_>(schema::users::table, uuid.0, conn)
 }
 
+#[inline(always)]
+pub fn get_rows<'a, Model, Table>(table: Table, conn: &PgConnection) -> Result<Vec<Model>, Error>
+ where
+ Table: RunQueryDsl<Model> + Query + LoadQuery<PgConnection, Model>,
+{
+ table.load::<Model>(conn)
+}
+
+
 
 /// Generic function for deleting a row from a given table.
 #[inline(always)]
@@ -131,4 +148,26 @@ where
 
 fn create_user(new_user: NewUser, conn: &PgConnection) -> Result<User, Error> {
  create_row::<User, NewUser,_>(schema::users::table, new_user, conn)
-}
+}
+
+//fn row_exists<'a, Model, Tab>(table: Tab, uuid: Uuid, conn: &PgConnection) -> Result<bool, Error>
+//where
+// Tab: FindDsl<Uuid> + Table,
+// <Tab as FindDsl<uuid::Uuid>>::Output: SelectQuery,
+// <Tab as FindDsl<uuid::Uuid>>::Output: QueryId,
+// <Tab as FindDsl<uuid::Uuid>>::Output: ValidSubselect<()>,
+// <Tab as FindDsl<Uuid>>::Output : SelectDsl<Exists<<Tab as FindDsl<Uuid>>::Output>>,
+// Find<Tab, Uuid>: LoadQuery<PgConnection, Model>,
+//// SelectStatement<(), Select=Exists<<Table as FindDsl<Uuid>>::Output>>: QueryFragment<Pg>//, SelectClause<Exists<<Table as FindDsl<uuid::Uuid>>::Output>>>: QueryFragment<Pg>
+//{
+//// table.find(uuid)
+//// .select(exists)
+//
+//// select(exists(table.filter(table.primary_key().eq(uuid))))
+// table
+//// .find(uuid)
+// .count()
+// .get_result::<i32>(conn)
+//}
+//
+//use diesel::QueryDsl;