LINQ的幫助下，在（）語句

Question

我需要幫助寫一個LINQ語句不一樣的下面的SQL查詢SQL ...

select col1, col2, col3 
from table1 
where col1 = 'foo' 
and col2 = 0 
and IsNull(col3, '') IN('A','') 

感謝

Answer 1

from t in context.table1 
where 
    t.col1 == "foo" 
&& t.col2 == 0 
&& (new string[]{"A", string.Empty}).Contains(t.col3.DefaultIfEmpty(string.Empty)) 
select new {t.col1, t.col2, t.col3}; 

Answer 2

var q = from row in YourTableObject 
     where row.col1 = "foo" 
       && row.col2 = 0 
       && (string.IsNullOrEmpty(row.col3) || row.col3 == "A") 
     select new { 
         col1, 
         col2, 
         col3 
        } 

Answer 3

的包含運營商是一個特殊的，你可以說沿線

List<string> col3s= new List<string>() { "A", "B" }; 

from c in table1 
where c.col1 = "foo" && && c.col2 = 0 && col3s.Contains(c.col3) 
select new { c.col1, c.col2, c.col3 };