Update

ConsoleApp2/Helpers/Database/DatabaseHelper.cs

@@ -0,0 +1,54 @@
+using System.Data;
+using MySqlConnector;
+
+namespace ConsoleApp2.Helpers.Database;
+
+public static class DatabaseHelper
+{
+    public static async Task<DataSet> QueryTableAsync(string connStr, string sql)
+    {
+        await using var conn = new MySqlConnection(connStr);
+        if(conn.State is not ConnectionState.Open)
+            await conn.OpenAsync();
+        await using var cmd = conn.CreateCommand();
+        cmd.CommandText = sql;
+        var ds = new DataSet();
+        var adapter = new MySqlDataAdapter(cmd).Fill(ds);
+        return ds;
+    }
+
+    public static async Task<object?> QueryScalarAsync(string connStr, string sql)
+    {
+        await using var conn = new MySqlConnection(connStr);
+        if(conn.State is not ConnectionState.Open)
+            await conn.OpenAsync();
+        await using var cmd = conn.CreateCommand();
+        cmd.CommandText = sql;
+        return await cmd.ExecuteScalarAsync();
+    }
+
+    public static async Task<int> NonQueryAsync(string connStr, string sql)
+    {
+        await using var conn = new MySqlConnection(connStr);
+        if(conn.State is not ConnectionState.Open)
+            await conn.OpenAsync();
+        await using var cmd = conn.CreateCommand();
+        cmd.CommandText = sql;
+        return await cmd.ExecuteNonQueryAsync();
+    }
+
+    public static async Task<int> TransactionAsync(string connStr, string sql, params MySqlParameter[] parameters)
+    {
+        await using var conn = new MySqlConnection(connStr);
+        if(conn.State is not ConnectionState.Open)
+            await conn.OpenAsync();
+        await using var trans = await conn.BeginTransactionAsync();
+        await using var cmd = conn.CreateCommand();
+        cmd.CommandText = sql;
+        cmd.Transaction = trans;
+        cmd.Parameters.AddRange(parameters);
+        var rows = await cmd.ExecuteNonQueryAsync();
+        await trans.CommitAsync();
+        return rows;
+    }
+}