將SQL語句轉換為Linq-2-Sql

Question

如何將以下SQL語句轉換為L2S？

SELECT DefaultCode, MAX(EffectiveDt) AS EffectiveDt
FROM tblDF_DefaultSetting
GROUP BY DefaultCode

Answer 1

您想在DefaultCode上使用GroupBy運算符，並使用Select運算符使用您感興趣的兩個值創建一個新的匿名類型。

dataContext.tblDF_DefaultSetting
    .GroupBy(x => x.DefaultCode)
    .Select(x => new { DefaultCode = x.Key, EffectiveDt = x.Max(x => x.EffectiveDt) });