/// <summary>
/// 构建搜索表达式
/// </summary>
/// <param name="builder"></param>
/// <param name="actionBuilder"></param>
/// <typeparam name="TSource"></typeparam>
/// <returns></returns>
public static IPagingQueryBuilder <TSource> Search <TSource> (this IPagingQueryBuilder <TSource> builder, Action <ISearchOptions <TSource> > actionBuilder)
{
var options = new SearchOptions <TSource> (builder.Parameter);
actionBuilder(options);
builder.Filter(options.BuildExpression());
return(builder);
}
/// <summary>
/// 增加 聚合结果
/// </summary>
/// <param name="builder"></param>
/// <param name="aggExpression"></param>
/// <typeparam name="TSource"></typeparam>
/// <typeparam name="TAggregate"></typeparam>
/// <returns></returns>
public static async Task <PageResult <TSource, TAggregate> > WithAggregateAsync <TSource, TAggregate> (this IPagingQueryBuilder <TSource> builder, Expression <Func <IGrouping <bool, TSource>, TAggregate> > aggExpression)
{
var aggregate = await builder.Query.GroupBy(t => true).Select(aggExpression).SingleAsync();
var result = await builder.ToPagingAsync();
return(new PageResult <TSource, TAggregate> (result, aggregate));
}
