Question

I am trying to write a linq query in my Database.cs file. I find it difficult. Is there any tool to convert sql to linq? I tried linqer but it is no good. Or could you help me in writing the following query in linq.

update table 
set field1='R', 
    field2='" + DateTime.Now.ToString("MM/dd/yyyy hh:mm:ss") + "', 
    field3 = '" + util.CleanStringInput(value1) + "'
where field1 = 'P' 
    and field3 = '" + value2 + "' 
    and field4 = (select max(field5) 
                  from table2 
                  where field6='" + value2 + "')

Answer 1

The easiest way would be to fetch the entities, set the properties and then save changes:

var maxFromTable2 = context.YourTables2.
                            Where(t2 => t2.field6 == value2).
                            Max(t2 => t2.field5);

var entitiesToUpdate = context.YourTables.
                               Where(t => t.field1 == "P" && 
                                          t.field3 == value2 && 
                                          t.field4 ==  maxFromTable2).
                               ToList();

foreach (var entityToUpdate in entitiesToUpdate)
{
    entityToUpdate.field1 = "R";
    entityToUpdate.field2 = DateTime.Now.ToString("MM/dd/yyyy hh:mm:ss");
}

context.SaveChanges();

NOTE: It is not clear from your question what table you are updating, so I assume by default that it is a table different from table2. It could help if you indicate whether you are using LINQ to SQL or Entity Framework (LINQ to Entitites). The current syntax is for EF.