How to Implement the Equivalent of SQL In() Using .Net

How do you implement the equivalent of SQL IN() using .net

using System;
using System.Linq;

static class SqlStyleExtensions
{
    public static bool In(this string me, params string[] set)
    {
       return set.Contains(me);
    }
}

Usage:

if (Variable.In("AC", "BC", "EA"))
{

} 

SQL Server in equivalent in .Net

Threre is no keyword, however you can use the following construct:

using System.Linq;
...
(new [] {12, 23, 45}).Contains(customerID)

Equivalent of SQL IN in VB.NET

After a bit of playing around, I have managed to find a nice solution:

Select Case True
    Case Array.IndexOf(New Integer() {2, 3}, SectionID) > -1 : SecondLineHolder.Attributes("style") = "color:#21720B"
    Case Array.IndexOf(New Integer() {8, 12}, PageID) > -1 : SecondLineHolder.Attributes("style") = "color:#1B45C2"
End Select

C# Version Of SQL LIKE

Regular expressions allow for everything that LIKE allows for, and much more, but have a completely different syntax. However, since the rules for LIKE are so simple(where % means zero-or-more characters and _ means one character), and both LIKE arguments and regular expressions are expressed in strings, we can create a regular expression that takes a LIKE argument (e.g. abc_ef% *usd) and turn it into the equivalent regular expression (e.g. \Aabc.ef.* \*usd\z):

@"\A" + new Regex(@"\.|\$|\^|\{|\[|\(|\||\)|\*|\+|\?|\\").Replace(toFind, ch => @"\" + ch).Replace('_', '.').Replace("%", ".*") + @"\z"

From that we can build a Like() method:

public static class MyStringExtensions
{
  public static bool Like(this string toSearch, string toFind)
  {
    return new Regex(@"\A" + new Regex(@"\.|\$|\^|\{|\[|\(|\||\)|\*|\+|\?|\\").Replace(toFind, ch => @"\" + ch).Replace('_', '.').Replace("%", ".*") + @"\z", RegexOptions.Singleline).IsMatch(toSearch);
  }
}

And hence:

bool willBeTrue = "abcdefg".Like("abcd_fg");
bool willAlsoBeTrue = "abcdefg".Like("ab%f%");
bool willBeFalse = "abcdefghi".Like("abcd_fg");

Is there a .NET equivalent to SQL Server's newsequentialid()

It should be possible to create a sequential GUID in c# or vb.net using an API call to UuidCreateSequential. The API declaration (C#) below has been taken from Pinvoke.net where you can also find a full example of how to call the function.

[DllImport("rpcrt4.dll", SetLastError=true)]
static extern int UuidCreateSequential(out Guid guid);

The MSDN article related to the UuidCreateSequential function can be found here which includes the prerequisites for use.

linq equivalent sql query not in (select query)

my first try using LiNQ in C#

var result = from y in aspnet_Users
            where !(
                        from x in tblUser
                        where  x.active == "true"
                        select x.UsersID
                    ).Contains(y.UserId)
            select y;                
            -- OR // select new { y.UserId, y.UserName};

SOURCE

• The NOT IN clause in LINQ to SQL

LINQ equivalent of SQL LIKE for text field with digits

This worked.

.Where(p => EF.Functions.Like(p.Value, "100[0-9][0-9][0-9][0-9]"))

Thanks to all the advice in the comments!

C# Equivalent of SQL Server DataTypes

This is for SQL Server 2005. There are updated versions of the table for SQL Server 2008, SQL Server 2008 R2, SQL Server 2012 and SQL Server 2014.

SQL Server Data Types and Their .NET Framework Equivalents

The following table lists Microsoft SQL Server data types, their equivalents in the common language runtime (CLR) for SQL Server in the System.Data.SqlTypes namespace, and their native CLR equivalents in the Microsoft .NET Framework.

.Where(oh => oh.Hierarchy.Contains("/12/"))

var resultset = from x in collection where new[] {2,3,4,5}.Contains(x) select x

var resultset = from x in collection where x >= 2 && x <= 5 select x