join lateral

src/backend/api/instance.rs

@@ -7,11 +7,16 @@ use crate::{
     },
     common::{
         instance::{
-            DbInstance, FollowInstanceParams, GetInstanceParams, InstanceView, InstanceView2,
+            DbInstance,
+            FollowInstanceParams,
+            GetInstanceParams,
+            InstanceView,
+            InstanceView2,
             UpdateInstanceParams,
         },
         user::LocalUserView,
-        ResolveObjectParams, SuccessResponse,
+        ResolveObjectParams,
+        SuccessResponse,
     },
 };
 use activitypub_federation::{config::Data, fetch::object_id::ObjectId};

src/backend/database/instance.rs

@@ -5,14 +5,14 @@ use crate::{
             IbisContext,
         },
         federation::objects::{
-            articles_collection::DbArticleCollection, instance_collection::DbInstanceCollection,
+            articles_collection::DbArticleCollection,
+            instance_collection::DbInstanceCollection,
         },
         utils::error::MyResult,
     },
     common::{
-        article::DbArticle,
         instance::{DbInstance, InstanceView, InstanceView2},
-        newtypes::{ArticleId, CommentId, InstanceId},
+        newtypes::{CommentId, InstanceId},
         user::DbPerson,
     },
 };
@@ -21,20 +21,9 @@ use activitypub_federation::{
     fetch::{collection_id::CollectionId, object_id::ObjectId},
 };
 use chrono::{DateTime, Utc};
-use diesel::{
-    associations::HasTable,
-    define_sql_function,
-    deserialize::{self, FromSql},
-    insert_into,
-    pg::{Pg, PgValue},
-    sql_types::Record,
-    update, AsChangeset, ExpressionMethods, Insertable, JoinOnDsl, NullableExpressionMethods,
-    QueryDsl, RunQueryDsl,
-};
+use diesel::*;
 use std::{fmt::Debug, ops::DerefMut};
 
-use super::array_agg;
-
 #[derive(Debug, Clone, Insertable, AsChangeset)]
 #[diesel(table_name = instance, check_for_backend(diesel::pg::Pg))]
 pub struct DbInstanceForm {
@@ -151,26 +140,28 @@ impl DbInstance {
 
     pub fn list(context: &Data<IbisContext>) -> MyResult<Vec<InstanceView>> {
         let mut conn = context.db_pool.get()?;
-        // select instance, array_agg(article) from instance left join article on instance.id=article.instance_id group by instance.id;
-        let res: Vec<_> = instance::table
-            .left_join(article::table.on(instance::id.eq(article::instance_id)))
-            .select((
-                instance::all_columns,
-                //array_agg(article::all_columns)
-                diesel::dsl::sql::<diesel::sql_types::Array<article::SqlType>>(
-                    "array_agg(article.*)",
-                ),
-            ))
-            .group_by(instance::id)
-            // TODO: throws invalid trait bound
-            .get_results::<(DbInstance, Vec<DbArticle>)>(conn.deref_mut())?;
-        Ok(res
-            .into_iter()
-            .map(|x| InstanceView {
-                instance: x.0,
-                articles: x.1,
-            })
-            .collect())
+        let res: Vec<_> = sql_query(
+            "SELECT
+                instance,
+                array_agg(a) as articles
+            FROM
+                instance
+                CROSS JOIN LATERAL (
+                    SELECT
+                        title
+                    FROM
+                        article
+                    WHERE
+                        instance.id = article.instance_id
+                    GROUP BY
+                        article.id
+                    LIMIT 5) a
+            GROUP BY
+                id;",
+        )
+        .select(InstanceView::as_select())
+        .get_results::<InstanceView>(conn.deref_mut())?;
+        Ok(res)
     }
 
     /// Read the instance where an article is hosted, based on a comment id.
@@ -188,16 +179,3 @@ impl DbInstance {
             .get_result(conn.deref_mut())?)
     }
 }
-
-define_sql_function!(fn array_agg<T: diesel::sql_types::SingleValue>(expr: T) -> Array<T>);
-
-// https://github.com/diesel-rs/diesel/discussions/3826
-impl FromSql<diesel::sql_types::Record<article::SqlType>, Pg> for DbArticle {
-    fn from_sql(value: PgValue<'_>) -> deserialize::Result<Self> {
-        //let mut bytes = value.as_bytes();
-        //let res: (i32,) = FromSql::<Record<article::SqlType>, Pg>::from_sql(value)?;
-
-        //Ok(Label1 { id: res.0 })
-        todo!()
-    }
-}

src/backend/database/mod.rs

@@ -4,7 +4,9 @@ use crate::backend::{
 };
 use diesel::{
     r2d2::{ConnectionManager, Pool},
-    PgConnection, QueryDsl, RunQueryDsl,
+    PgConnection,
+    QueryDsl,
+    RunQueryDsl,
 };
 use std::ops::DerefMut;
 

src/common/article.rs

@@ -5,6 +5,7 @@ use super::{
     user::DbPerson,
 };
 use chrono::{DateTime, Utc};
+use diesel::QueryableByName;
 use serde::{Deserialize, Serialize};
 use sha2::{Digest, Sha256};
 use uuid::Uuid;
@@ -39,7 +40,7 @@ pub struct DbArticleView {
     pub latest_version: EditVersion,
 }
 
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, QueryableByName)]
 #[cfg_attr(feature = "ssr", derive(Queryable, Selectable, Identifiable))]
 #[cfg_attr(feature = "ssr", diesel(table_name = article, check_for_backend(diesel::pg::Pg), belongs_to(DbInstance, foreign_key = instance_id)))]
 pub struct DbArticle {

src/common/instance.rs

@@ -4,13 +4,15 @@ use super::{
     user::{DbPerson, LocalUserView},
 };
 use chrono::{DateTime, Utc};
+use diesel::QueryableByName;
 use serde::{Deserialize, Serialize};
 use smart_default::SmartDefault;
 use url::Url;
 #[cfg(feature = "ssr")]
 use {
     crate::backend::{
-        database::schema::instance, federation::objects::articles_collection::DbArticleCollection,
+        database::schema::instance,
+        federation::objects::articles_collection::DbArticleCollection,
         federation::objects::instance_collection::DbInstanceCollection,
     },
     activitypub_federation::fetch::{collection_id::CollectionId, object_id::ObjectId},
@@ -18,7 +20,7 @@ use {
     doku::Document,
 };
 
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, QueryableByName)]
 #[cfg_attr(feature = "ssr", derive(Queryable, Selectable, Identifiable))]
 #[cfg_attr(feature = "ssr", diesel(table_name = instance, check_for_backend(diesel::pg::Pg)))]
 pub struct DbInstance {
@@ -52,10 +54,12 @@ impl DbInstance {
 }
 
 #[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
-#[cfg_attr(feature = "ssr", derive(Queryable))]
-#[cfg_attr(feature = "ssr", diesel(table_name = article, check_for_backend(diesel::pg::Pg)))]
+#[cfg_attr(feature = "ssr", derive(Queryable, QueryableByName))]
+#[cfg_attr(feature = "ssr", diesel(check_for_backend(diesel::pg::Pg)))]
 pub struct InstanceView {
+    #[diesel(embed)]
     pub instance: DbInstance,
+    #[diesel(embed)]
     pub articles: Vec<DbArticle>,
 }
 

src/frontend/api/instance.rs

@@ -1,13 +1,7 @@
 use super::{result_to_option, ApiClient};
 use crate::common::{
     article::{DbArticle, SearchArticleParams},
-    instance::{
-        DbInstance,
-        FollowInstanceParams,
-        InstanceView2,
-        SiteView,
-        UpdateInstanceParams,
-    },
+    instance::{DbInstance, FollowInstanceParams, InstanceView2, SiteView, UpdateInstanceParams},
     Notification,
     ResolveObjectParams,
     SuccessResponse,