La in dapper, och routing. fixade upp lite exempelsidor

Server/Business/Services/DatabaseService.cs

@@ -0,0 +1,45 @@
+using Bibblan.Models;
+using Bibblan.ViewModels;
+using Dapper;
+using Microsoft.Extensions.Options;
+using Npgsql;
+
+namespace Bibblan.Business.Services
+{
+
+    public class BookFilter
+    {
+        public int? Author;
+    }
+
+    public class DatabaseService
+    {
+        BibblanOptions settings;
+        public DatabaseService(IOptions<BibblanOptions> options) {
+            settings = options.Value;
+        }
+
+        public IEnumerable<Books> GetBooks(int count, BookFilter filter = null)
+        {
+            var conn = new NpgsqlConnection(settings.BibblanConnection);
+            var query = "select * from books";
+            if(filter != null)
+            {
+                query += " where ";
+                if(filter.Author != null)
+                {
+                    query += $"id in (select book from books_authors_link where author = {filter.Author})";
+                }
+            }
+            return conn.Query<Books>(query).Take(count).ToList();
+        }
+
+        public IEnumerable<AuthorVm> GetAuthors(int count)
+        {
+            var query = "select a.id, a.name, count(bal.*) as bookcount\r\nfrom authors a\r\nleft join books_authors_link bal on a.id  = bal.author\r\ngroup by a.id , a.name ";
+            var conn = new NpgsqlConnection(settings.BibblanConnection);
+            return conn.Query<AuthorVm>(query).Take(count).ToList();
+
+        }
+    }
+}