Add project files.

Media.JoshHeaps.Net/DbExecutor.cs

@@ -0,0 +1,81 @@
+using Npgsql;
+
+namespace Media.JoshHeaps.Net;
+
+public class DbExecutor(IConfiguration config)
+{
+    private string ConnectionString => config["connectionString"]!;
+
+    // Returns a single value (first column, first row)
+    public async Task<T?> ExecuteAsync<T>(string query, object? parameters = null)
+    {
+        parameters ??= new();
+        using var conn = new NpgsqlConnection(ConnectionString);
+        await conn.OpenAsync();
+        using var cmd = new NpgsqlCommand(query, conn);
+
+        // Add parameters if provided
+        foreach (var prop in parameters.GetType().GetProperties())
+        {
+            cmd.Parameters.AddWithValue($"@{prop.Name}", prop.GetValue(parameters) ?? DBNull.Value);
+        }
+
+        var result = await cmd.ExecuteScalarAsync();
+
+        if (result == null || result == DBNull.Value)
+            return default;
+
+        return (T)result;
+    }
+
+    // Returns a list of values (first column from all rows)
+    public async Task<List<T>> ExecuteListAsync<T>(string query, object? parameters = null)
+    {
+        parameters ??= new();
+        using var conn = new NpgsqlConnection(ConnectionString);
+        await conn.OpenAsync();
+        using var cmd = new NpgsqlCommand(query, conn);
+
+        foreach (var prop in parameters.GetType().GetProperties())
+        {
+            cmd.Parameters.AddWithValue($"@{prop.Name}", prop.GetValue(parameters) ?? DBNull.Value);
+        }
+
+        using var reader = await cmd.ExecuteReaderAsync();
+
+        List<T> results = [];
+
+        while (await reader.ReadAsync())
+        {
+            if (reader.IsDBNull(0))
+                continue;
+
+            results.Add((T)reader.GetValue(0));
+        }
+
+        return results;
+    }
+
+    // Returns a data reader for custom mapping (caller must dispose)
+    public async Task<T?> ExecuteReaderAsync<T>(string query, Func<NpgsqlDataReader, T?> mapper, object? parameters = null)
+    {
+        parameters ??= new();
+        using var conn = new NpgsqlConnection(ConnectionString);
+        await conn.OpenAsync();
+        using var cmd = new NpgsqlCommand(query, conn);
+
+        foreach (var prop in parameters.GetType().GetProperties())
+        {
+            cmd.Parameters.AddWithValue($"@{prop.Name}", prop.GetValue(parameters) ?? DBNull.Value);
+        }
+
+        using var reader = await cmd.ExecuteReaderAsync();
+
+        if (await reader.ReadAsync())
+        {
+            return mapper(reader);
+        }
+
+        return default;
+    }
+}