C# .NET6 API 项目中的 Dapper 不支持 TimeOnly 数据类型

Question

我在 ASP.NET Core 6 Web API 项目中使用 Dapper，并以 SQL Server 2016 数据库作为后端。Dapper 的方法ExecuteScalar返回错误

System.TimeOnly 类型的成员 DepartureTime 不能用作参数值

有什么解决方法吗？

public virtual int Create(TModel entity)
{
    int result = -1;
    var insertQuery = QueryGenerator.GenerateInsertQuery(typeof(TModel));
    var factory = new SqlServerDbConnectionFactory(connectionString);
    var profiler = CustomDbProfiler.Current;

    using (var connection = ProfiledDbConnectionFactory.New(factory, profiler))
    {
        try
        {
            if (connection.State == ConnectionState.Closed)
            {
                connection.ConnectionString = connectionString;
                connection.Open();
            }

            result =  connection.ExecuteScalar<int>(insertQuery, entity, transaction: null); // Throwing error
        }
        catch (Exception e)
        {
            var sql = profiler.GetCommands();
            throw;
        }
    }

    return result;
}

insertQuery包含以下查询：

INSERT INTO [Flight] ([FlightNumber], [SourceCode], [DestinCode],[DepartureTime], [EffectDate], [Stops], [TravelMinutes]) 
VALUES (@FlightNumber, @SourceCode, @DestinCode, @DepartureTime, @EffectDate, @Stops, @TravelMinutes);
SELECT SCOPE_IDENTITY()

entity属于类型FlightModel：

public class FlightModel
{
    public int Id { get; set; }
    public string FlightNumber{ get; set; }
    public string SourceCode{ get; set; }
    public string DestinCode { get; set; }
    public TimeOnly DepartureTime{ get; set; }
    public DateOnly EffectDate { get; set; }
    public int Stops{ get; set; }
    public int TravelMinutes { get; set; }
}

Answer 1

从这里开始，创建您自己的类型处理程序：

将以下内容添加到您的配置中：

SqlMapper.AddTypeHandler(new SqlTimeOnlyTypeHandler());

public class SqlTimeOnlyTypeHandler : SqlMapper.TypeHandler<TimeOnly>
{
    public override void SetValue(IDbDataParameter parameter, TimeOnly time)
    {
        parameter.Value = time.ToString();
    }

    public override TimeOnly Parse(object value)
    {
        return TimeOnly.FromTimeSpan((TimeSpan)value);
    }
}