Update database handling code (#247)

web/backend/Database/Database.Connection/Repository.cs

@@ -0,0 +1,21 @@
+using System.Data.Common;
+
+namespace Database.Connection;
+
+/// <summary>
+///     Base class for Dapper-based repositories, providing shared connection creation for derived
+///     repository implementations.
+/// </summary>
+public abstract class DapperRepository(ISqlConnectionFactory connectionFactory)
+{
+    /// <summary>
+    ///     Creates and opens a new database connection using the configured <see cref="ISqlConnectionFactory" />.
+    /// </summary>
+    /// <exception cref="DbException">Thrown when the connection cannot be opened.</exception>
+    protected async Task<DbConnection> CreateConnection()
+    {
+        DbConnection connection = connectionFactory.CreateConnection();
+        await connection.OpenAsync();
+        return connection;
+    }
+}