/// <summary>
/// 返回一个Query节
/// </summary>
/// <typeparam name="T"></typeparam>
/// <returns></returns>
public QuerySection <T> From <T>(TableRelation <T> relation)
where T : Entity
{
//重新实例化一个Query
var query = new QuerySection <T>(relation.GetFromSection(), dbProvider, this);
//处理前n条
if (relation.GetTopSize() > 0)
{
query = query.GetTop(relation.GetTopSize());
}
return(query);
}
/// <summary>
/// 选择前n条
/// </summary>
/// <param name="topSize"></param>
/// <returns></returns>
public TopSection <T> GetTop(int topSize)
{
return(query.GetTop(topSize));
}
/// <summary>
/// 返回ISourceReader
/// </summary>
/// <returns></returns>
public SourceReader ToReader(int topSize)
{
return(query.GetTop(topSize).ToReader());
}
/// <summary>
/// 返回T
/// </summary>
/// <returns></returns>
public T ToSingle <T>()
where T : class
{
return(query.GetTop(1).ToReader().ConvertTo <T>()[0]);
}
