Linq/EF/lambda Group by/Order by 多个字段详细用法

Linq/EF/lambda Group by/Order by 多个字段详细用法

 

1)单个字段Group by:

//a.Key类型与a.Province字段类型一样 

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.GroupBy(a => a.Province).Select(a => a.Key).ToList(); 

2)多个字段Group by:

//此时返回的数据列表需要自己转换 

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.GroupBy(a => new { a.Date, a.Week }).Select(a => a.Key).ToList();

3)单个字段Order by:

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.OrderBy(a => a.Date).ToList()

4)多个字段Order by:

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.OrderBy(a => a.Date).ThenBy(a => a.EndTime).ThenBy(a => a.StartTime).ToList()

5)多个字段Order by倒序:

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.OrderByDescending(a => a.Date).ThenByDescending(a => a.EndTime).ThenByDescending(a => a.StartTime).ToList()
版权所有:jory—经得起折磨,耐得住寂寞
原文地址:https://www.cnblogs.com/zengpeng/p/9848315.html