Entity Framework 6 ToString(), formatting (DateTime format), query intercept

Question

I`m not found correct way to search with linq2sql in DateTime (DateTime?) fields.

db.Items.Where(x => x.DateTime1.ToSt         


        

Answer 1

Why don't you just use the Year and Month property? You should be able to convert the string input into Year and Month number. Then you do something like:

db.Items.Where(x => 
   x.DateTime1.Value.Year == 2014 
   && x.DateTime1.Value.Month == 8)

It will simply be converted to:

WHERE (2014 = (DATEPART (year, [Extent1].[Date]))) 
AND     (8 = (DATEPART (month, [Extent1].[Date])))

update

You can use SqlFunctions.DatePart and DbFunctions.Right to produce following format yyyy.mm.dd.

db.Items.Where(x => 
    (SqlFunctions.DatePart("yyyy", x.DateTime) + "."
    + DbFunctions.Right("0" + SqlFunctions.DatePart("m", x.DateTime1), 2) + "."
    + DbFunctions.Right("0" + SqlFunctions.DatePart("d", x.DateTime1), 2))
    .Contains("2014.08"));

Answer 2

1. Function in MS SQL

CREATE FUNCTION [dbo].[ToString](@P sql_variant)
RETURNS NVARCHAR(20)
AS
BEGIN
    IF (sql_variant_property(@P, 'BaseType') = 'datetime')
        RETURN CONVERT(NVARCHAR(10), @P, 102) + ' ' + CONVERT(NVARCHAR(8), @P, 108);

RETURN CAST(@P as NVARCHAR(max));
END

1. Create sql execution Interceptor

public class DbCommandInterceptor  : IDbCommandInterceptor 
{
    public void ReaderExecuting(DbCommand command, DbCommandInterceptionContext<DbDataReader> interceptionContext)
    {
        if (command.CommandText.IndexOf("CAST") != -1)
        {
            command.CommandText = command.CommandText.Replace("CAST(", "dbo.ToString(");
            command.CommandText = command.CommandText.Replace("] AS nvarchar(max))", "])");

        }
    }

}

1. Add Interceptor to DbContext

public class DB : DbContext
{
    public DB(): base(@"Data Source=localhost\SQLEXPRESS;Initial Catalog=EFTest")
    {
        DbInterception.Add(new DbCommandInterceptor ());
    }
}