Add relation between blogs and authors

migrations/2018-04-23-111655_create_blog_authors/down.sql

@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+DROP TABLE blog_authors;

migrations/2018-04-23-111655_create_blog_authors/up.sql

@@ -0,0 +1,7 @@
+-- Your SQL goes here
+CREATE TABLE blog_authors (
+    id SERIAL PRIMARY KEY,
+    blog_id INTEGER REFERENCES blogs(id) ON DELETE CASCADE NOT NULL,
+    author_id INTEGER REFERENCES users(id) ON DELETE CASCADE NOT NULL,
+    is_owner BOOLEAN NOT NULL DEFAULT 'f'
+)

src/models/blog_authors.rs

@@ -0,0 +1,36 @@
+use diesel;
+use diesel::{QueryDsl, RunQueryDsl, ExpressionMethods, PgConnection};
+use schema::blog_authors;
+
+#[derive(Queryable, Identifiable)]
+pub struct BlogAuthor {
+    pub id: i32,
+    pub blog_id: i32,
+    pub author_id: i32,
+    pub is_owner: bool,
+}
+
+#[derive(Insertable)]
+#[table_name = "blog_authors"]
+pub struct NewBlogAuthor {
+    pub blog_id: i32,
+    pub author_id: i32,
+    pub is_owner: bool,
+}
+
+impl BlogAuthor {
+    pub fn insert (conn: &PgConnection, new: NewBlogAuthor) -> BlogAuthor {
+        diesel::insert_into(blog_authors::table)
+            .values(new)
+            .get_result(conn)
+            .expect("Error saving new blog")
+    }
+
+    pub fn get(conn: &PgConnection, id: i32) -> Option<BlogAuthor> {
+        blog_authors::table.filter(blog_authors::id.eq(id))
+            .limit(1)
+            .load::<BlogAuthor>(conn)
+            .expect("Error loading blog by id")
+            .into_iter().nth(0)
+    }
+}

src/models/mod.rs

@@ -1,3 +1,4 @@
+pub mod blog_authors;
 pub mod blogs;
 pub mod instance;
 pub mod user;

src/schema.rs

@@ -1,3 +1,12 @@
+table! {
+    blog_authors (id) {
+        id -> Int4,
+        blog_id -> Int4,
+        author_id -> Int4,
+        is_owner -> Bool,
+    }
+}
+
 table! {
     blogs (id) {
         id -> Int4,
@@ -36,10 +45,13 @@ table! {
     }
 }
 
+joinable!(blog_authors -> blogs (blog_id));
+joinable!(blog_authors -> users (author_id));
 joinable!(blogs -> instances (instance_id));
 joinable!(users -> instances (instance_id));
 
 allow_tables_to_appear_in_same_query!(
+    blog_authors,
     blogs,
     instances,
     users,