Add operations & node_type check triggers

migrations/2024-05-09-173338_initial_db_setup/down.sql

@@ -10,4 +10,6 @@ DROP TABLE images;
 DROP TABLE meal_images;
 
 DROP TYPE node_type;
+DROP FUNCTION check_node_type();
+DROP FUNCTION check_linked_restaurants();
 DROP EXTENSION postgis CASCADE;

migrations/2024-05-09-173338_initial_db_setup/up.sql

@@ -4,17 +4,53 @@ CREATE EXTENSION postgis;
 CREATE TABLE nodes(
 	id SERIAL PRIMARY KEY,
 	name VARCHAR(100) NOT NULL,
-	type NODE_TYPE NOT NULL,
+	node_type NODE_TYPE NOT NULL,
 	coordinates GEOMETRY(POINT,4326) NOT NULL
 );
 
+CREATE OR REPLACE FUNCTION check_linked_restaurants()
+RETURNS TRIGGER AS $$
+BEGIN
+    -- Check if the node is being updated from 'restaurant' to a different type
+    IF OLD.node_type = 'restaurant' AND NEW.node_type <> 'restaurant' THEN
+        -- Check if the node still has linked restaurants
+        IF EXISTS (SELECT 1 FROM restaurants WHERE node_id = OLD.id) THEN
+            RAISE EXCEPTION 'Cannot change node type from "restaurant" as it still has linked restaurants';
+        END IF;
+    END IF;
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER check_linked_restaurants_trigger
+BEFORE UPDATE OF node_type ON nodes
+FOR EACH ROW
+EXECUTE FUNCTION check_linked_restaurants();
+
+
 CREATE TABLE restaurants(
 	id SERIAL PRIMARY KEY,
 	node_id INTEGER REFERENCES nodes(id) NOT NULL,
 	address VARCHAR(30) NOT NULL,
-	price INTEGER CHECK ( price >= 0 AND price <= 10 ) NOT NULL
+	price SMALLINT CHECK ( price >= 0 AND price <= 10 ) NOT NULL
 );
 
+CREATE FUNCTION check_node_type()
+RETURNS TRIGGER AS $$
+BEGIN
+	-- Check if the node referenced by the foreign key is of type 'restaurant'
+    IF (SELECT node_type FROM nodes WHERE id = NEW.node_id) <> 'restaurant' THEN
+        RAISE EXCEPTION 'The referenced node has not type "restaurant"';
+    END IF;
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER enforce_node_type
+BEFORE INSERT OR UPDATE ON restaurants
+FOR EACH ROW
+EXECUTE FUNCTION check_node_type();
+
 CREATE TABLE images(
 	id SERIAL PRIMARY KEY,
 	url VARCHAR(50) NOT NULL
@@ -41,7 +77,7 @@ CREATE TABLE meals(
 	restaurant_rating_id INTEGER REFERENCES restaurant_ratings(id) NOT NULL,
 	user_id INTEGER REFERENCES users(id) NOT NULL,
 	name VARCHAR(30) NOT NULL,
-	rating INTEGER CHECK ( rating >= 0 AND rating <= 10 ) NOT NULL,
+	rating SMALLINT CHECK ( rating >= 0 AND rating <= 10 ) NOT NULL,
 	price DECIMAL(12,2) CHECK (price >= 0) NOT NULL,
 	price_currency VARCHAR(1) CHECK (TRIM(price_currency) <> '') NOT NULL,
 	note VARCHAR(100) NOT NULL DEFAULT '',

patches/schema.patch

@@ -1,6 +1,21 @@
---- src/full_schema.rs	2024-05-10 11:34:46.376360145 +0200
-+++ src/schema.rs	2024-05-10 11:34:24.009031704 +0200
-@@ -52,13 +52,12 @@
+--- src/full_schema.rs	2024-05-10 22:44:39.336282167 +0200
++++ src/schema.rs	2024-05-10 22:45:22.991271745 +0200
+@@ -1,14 +1,10 @@
+ // @generated automatically by Diesel CLI.
+ 
+ pub mod sql_types {
+     #[derive(diesel::query_builder::QueryId, diesel::sql_types::SqlType)]
+-    #[diesel(postgres_type(name = "geometry"))]
+-    pub struct Geometry;
+-
+-    #[derive(diesel::query_builder::QueryId, diesel::sql_types::SqlType)]
+     #[diesel(postgres_type(name = "node_type"))]
+     pub struct NodeType;
+ }
+ 
+ diesel::table! {
+     use diesel::sql_types::*;
+@@ -52,13 +48,12 @@
  }
  
  diesel::table! {
@@ -13,4 +28,4 @@
          id -> Int4,
          #[max_length = 100]
          name -> Varchar,
-         #[sql_name = "type"]
+         node_type -> NodeType,

src/main.rs

@@ -3,7 +3,12 @@ extern crate diesel;
 
 mod db;
 mod models;
+mod ops;
 mod schema;
-use diesel::prelude::*;
 
-fn main() {}
+fn main() {
+    ops::node_ops::create_node();
+    ops::restaurant_ops::create_restaurant();
+    // ops::node_ops::update_node();
+    ops::node_ops::show_nodes();
+}

src/models.rs

@@ -1,4 +1,4 @@
-use crate::schema::nodes;
+use crate::schema::{nodes, restaurants};
 use diesel::prelude::*;
 use postgis_diesel::types::Point;
 
@@ -13,6 +13,30 @@ pub enum NodeType {
 #[diesel(table_name = nodes)]
 pub struct NewNode<'a> {
     pub name: &'a str,
-    pub type_: NodeType,
+    pub node_type: NodeType,
     pub coordinates: Point,
 }
+
+#[derive(Debug, Queryable, AsChangeset)]
+pub struct Node {
+    pub id: i32,
+    pub name: String,
+    pub node_type: NodeType,
+    pub coordinates: Point,
+}
+
+#[derive(Insertable)]
+#[diesel(table_name = restaurants)]
+pub struct NewRestaurant<'a> {
+    pub node_id: i32,
+    pub address: &'a str,
+    pub price: i16,
+}
+
+#[derive(Debug, Queryable, AsChangeset)]
+pub struct Restaurant {
+    pub id: i32,
+    pub node_id: i32,
+    pub address: String,
+    pub price: i16,
+}

src/ops.rs

@@ -0,0 +1,2 @@
+pub mod node_ops;
+pub mod restaurant_ops;

src/ops/node_ops.rs

@@ -0,0 +1,55 @@
+use crate::db::establish_connection;
+use crate::models::*;
+use diesel::prelude::*;
+
+pub fn create_node() {
+    use crate::schema::nodes::dsl::*;
+
+    let mut conn = establish_connection();
+
+    let new_node = NewNode {
+        name: "Foo",
+        node_type: NodeType::Restaurant,
+        coordinates: postgis_diesel::types::Point {
+            x: 0.0,
+            y: 0.0,
+            srid: Some(4326),
+        },
+    };
+
+    diesel::insert_into(nodes)
+        .values(&new_node)
+        .execute(&mut conn)
+        .expect("Error saving new Node");
+}
+
+pub fn update_node() {
+    use crate::schema::nodes::dsl::*;
+
+    let node_id = 1;
+    let mut conn = establish_connection();
+
+    let node = Node {
+        id: node_id,
+        name: "Bar".to_string(),
+        node_type: NodeType::Marker,
+        coordinates: postgis_diesel::types::Point {
+            x: 6.9,
+            y: 0.0,
+            srid: Some(4326),
+        },
+    };
+
+    diesel::update(nodes.find(node_id))
+        .set(&node)
+        .execute(&mut conn)
+        .expect("Error saving new Node");
+}
+
+pub fn show_nodes() {
+    use crate::schema::nodes::dsl::*;
+
+    let mut conn = establish_connection();
+    let results = nodes.load::<Node>(&mut conn).expect("Error loading Nodes");
+    println!("{:?}", results);
+}

src/ops/restaurant_ops.rs

@@ -0,0 +1,51 @@
+use crate::db::establish_connection;
+use crate::models::*;
+use diesel::prelude::*;
+
+pub fn create_restaurant() {
+    use crate::schema::restaurants::dsl::*;
+
+    let mut conn = establish_connection();
+
+    let new_node = NewRestaurant {
+        node_id: 1,
+        address: "Hauptstraße 8",
+        price: 1,
+    };
+
+    diesel::insert_into(restaurants)
+        .values(&new_node)
+        .execute(&mut conn)
+        .expect("Error saving new Node");
+}
+
+// pub fn update_node() {
+//     use crate::schema::nodes::dsl::*;
+//
+//     let node_id = 1;
+//     let mut conn = establish_connection();
+//
+//     let node = Node {
+//         id: node_id,
+//         name: "Bar".to_string(),
+//         type_: NodeType::Restaurant,
+//         coordinates: postgis_diesel::types::Point {
+//             x: 6.9,
+//             y: 0.0,
+//             srid: Some(4326),
+//         },
+//     };
+//
+//     diesel::update(nodes.find(node_id))
+//         .set(&node)
+//         .execute(&mut conn)
+//         .expect("Error saving new Node");
+// }
+//
+// pub fn show_nodes() {
+//     use crate::schema::nodes::dsl::*;
+//
+//     let mut conn = establish_connection();
+//     let results = nodes.load::<Node>(&mut conn).expect("Error loading Nodes");
+//     println!("{:?}", results);
+// }

src/schema.rs

@@ -1,10 +1,6 @@
 // @generated automatically by Diesel CLI.
 
 pub mod sql_types {
-    #[derive(diesel::query_builder::QueryId, diesel::sql_types::SqlType)]
-    #[diesel(postgres_type(name = "geometry"))]
-    pub struct Geometry;
-
     #[derive(diesel::query_builder::QueryId, diesel::sql_types::SqlType)]
     #[diesel(postgres_type(name = "node_type"))]
     pub struct NodeType;
@@ -41,7 +37,7 @@ diesel::table! {
         user_id -> Int4,
         #[max_length = 30]
         name -> Varchar,
-        rating -> Int4,
+        rating -> Int2,
         price -> Numeric,
         #[max_length = 1]
         price_currency -> Varchar,
@@ -60,8 +56,7 @@ diesel::table! {
         id -> Int4,
         #[max_length = 100]
         name -> Varchar,
-        #[sql_name = "type"]
-        type_ -> NodeType,
+        node_type -> NodeType,
         coordinates -> Geometry,
     }
 }
@@ -88,7 +83,7 @@ diesel::table! {
         node_id -> Int4,
         #[max_length = 30]
         address -> Varchar,
-        price -> Int4,
+        price -> Int2,
     }
 }