问Dapper“异步”和“等待使用”

EN

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Threading.Tasks;
using Dapper;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using Outible.API.Model;
using Outible.DataAccess.Interfaces;

namespace Outible.DataAccess.Models
{
    public class Db : IDb
    {
        private readonly IOptionsMonitor<ConnectionStrings> _connectionStrings;
        private readonly ILogger<Db> _logger;

        public Db(IOptionsMonitor<ConnectionStrings> connectionStrings, ILogger<Db> logger)
        {
            _connectionStrings = connectionStrings;
            _logger = logger;
        }

        private async Task<T> CommandAsync<T>(Func<IDbConnection, IDbTransaction, int, Task<T>> command)
        {
            var connection = new SqlConnection(_connectionStrings.CurrentValue.MainDatabase);
            await connection.OpenAsync().ConfigureAwait(false);
            await using var transaction = await connection.BeginTransactionAsync();
            try
            {
                var result = await command(connection, transaction, 300).ConfigureAwait(false);

                await transaction.CommitAsync().ConfigureAwait(false);

                return result;
            }
            catch (Exception ex)
            {
                await transaction.RollbackAsync().ConfigureAwait(false);
                _logger.LogError(ex, "Rolled back transaction");
                throw;
            }
        }

        public Task<int> ExecuteAsync(string sql, object parameters)
        {
            return CommandAsync((conn, trn, timeout) => conn.ExecuteAsync(sql, parameters, trn, timeout));
        }

        public Task<T> GetAsync<T>(string sql, object parameters)
        {
            return CommandAsync((conn, trn, timeout) => conn.QuerySingleOrDefaultAsync<T>(sql, parameters, trn, timeout));
        }

        public Task<IEnumerable<T>> SelectAsync<T>(string sql, object parameters)
        {
            return CommandAsync((conn, trn, timeout) => conn.QueryAsync<T>(sql, parameters, trn, timeout));
        }
    }
}