C # method Rollup for generating unique values

One, build in. NET

1, using the Guid () function provided directly by the. NET Framework, this method is very widely used. A GUID (Global uniform identifier) is a number generated on a single machine that guarantees that no duplicate GUID values are generated for any two computers in the same space-time (that is, all machines are guaranteed to be unique). The introduction of GUIDs is not a specific statement here, so you can check out MSDN yourself for a closer look. The code is as follows:

The code is as follows:
Using System;
Using System.Collections.Generic;
Using System.Linq;
Using System.Text;

Namespace ConsoleApplication1
{
Class Program
{
static void Main (string[] args)
{
String _guid = GetGuid ();
Console.WriteLine ("Unique code: {0}\t Length: {1}\n Remove connector: {2}", _guid, _guid.) Length, _guid. Replace ("-", ""));

String uniqueidstring = Guidto16string ();
Console.WriteLine ("Unique code: {0}\t length: {1}", uniqueidstring, Uniqueidstring.length);

Long Uniqueidlong = Guidtolongid ();
Console.WriteLine ("Unique code: {0}\t length: {1}", Uniqueidlong, Uniqueidlong.tostring (). Length);

}

<summary>
32-digit number separated by hyphens
</summary>
<returns></returns>
private static string GetGuid ()
{
System.Guid GUID = new GUID ();
GUID = Guid.NewGuid ();
The return GUID. ToString ();
}

<summary>
Gets a unique 16-bit string based on the GUID
</summary>
<param name=\ "guid\" ></param>
<returns></returns>
public static string Guidto16string ()
{
Long i = 1;
foreach (Byte b in Guid.NewGuid (). Tobytearray ())
I *= ((int) b + 1);

return string. Format ("{0:x}", i-datetime.now.ticks);
}

<summary>
Gets a 19-bit unique number sequence based on a GUID
</summary>
<returns></returns>
public static long Guidtolongid ()
{
byte[] buffer = Guid.NewGuid (). Tobytearray ();
Return Bitconverter.toint64 (buffer, 0);
}

}
}

2. Generated with DateTime.Now.ToString ("Yyyymmddhhmmssms") and the RNGCryptoServiceProvider () provided by the. NET Framework, the code is as follows:

The code is as follows:
Using System;
Using System.Collections.Generic;
Using System.Linq;
Using System.Text;

Using System.Threading;

Namespace ConsoleApplication1
{
Class Program
{
static void Main (string[] args)
{
String uniquenum = Generateordernumber ();
Console.WriteLine ("Unique code: {0}\t length: {1}", Uniquenum, Uniquenum.length);

Tests whether duplicates are generated
Console.WriteLine ("Time +rngcryptoserviceprovider () combines the generated unique values, as follows:");
String _tempnum = String. Empty;
for (int i = 0; i <; i++)
{
String uNum = Generateordernumber ();
Console.WriteLine (UNum);
if (string. Equals (UNum, _tempnum))
{
Console.WriteLine ("Duplicate on value exists, press ENTER to continue");
Console.readkey ();
}

The current thread of sleep is for inertia, and thus does not produce duplicate values. You can comment it out and test it.
Thread.Sleep (300);

_tempnum = UNum;
}

}

<summary>
Unique order number generation
</summary>
<returns></returns>
public static string Generateordernumber ()
{
String strdatetimenumber = DateTime.Now.ToString ("yyyymmddhhmmssms");
String strrandomresult = Nextrandom (1000, 1). ToString ();

return strdatetimenumber + Strrandomresult;
}

<summary>
Reference: RNGCryptoServiceProvider examples on MSDN
</summary>
<param name= "Numseeds" ></param>
<param name= "Length" ></param>
<returns></returns>
private static int nextrandom (int numseeds, int length)
{
Create a byte array to hold the random value.
byte[] Randomnumber = new Byte[length];
Create a new instance of the RNGCryptoServiceProvider.
System.Security.Cryptography.RNGCryptoServiceProvider rng = new System.Security.Cryptography.RNGCryptoServiceProvider ();
Fill the array with a random value.
Rng. GetBytes (Randomnumber);
Convert the byte to a uint value to make the modulus operation easier.
UINT Randomresult = 0x0;
for (int i = 0; i < length; i++)
{
Randomresult |= (UINT) randomnumber[i] << ((length-1-i) * 8));
}

return (int) (randomresult% numseeds) + 1;
}
}
}

3. Use [0-9a-z] + guid.newguid () to combine a unique string that generates a specific number of digits, with the following code:

The code is as follows:
Using System;
Using System.Collections.Generic;
Using System.Linq;
Using System.Text;

Namespace ConsoleApplication1
{
Class Program
{
static void Main (string[] args)
{
String uniquetext = Generateuniquetext (8);
Console.WriteLine ("Unique code: {0}\t length: {1}", Uniquetext, Uniquetext.length);

Tests whether duplicates are generated
Console.WriteLine ("A unique value generated by [0-9a-z] + newguid (), as follows:");
ilist<string> list = new list<string> ();
for (int i = 1; i <=; i++)
{
String _ut = Generateuniquetext (8);
Console.WriteLine ("{0}\t{1}", List. Count, _ut);
if (list. Contains (_ut))
{
Console.WriteLine ("{0} value is duplicated", _ut);
Console.readkey ();
}

List. ADD (_ut);

if (i% 200 = = 0)
//{
Console.WriteLine ("No duplicates, press the ENTER key to look down");
Console.readkey ();
//}
}

List. Clear ();
}

<summary>
A unique string that generates a specific number of digits
</summary>
<param name= "num" > specific number of digits </param>
<returns></returns>
public static string generateuniquetext (int num)
{
String Randomresult = String. Empty;
String readystr = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
char[] Rtn = new Char[num];
Guid gid = Guid.NewGuid ();
var ba = gid. Tobytearray ();
for (var i = 0; i < num; i++)
{
Rtn[i] = readystr[((Ba[i] + ba[num + i])% 35)];
}

foreach (char R in RTN)
{
Randomresult + = r;
}

return randomresult;
}

}
}

4, with a single example of the implementation of the [0-9a-z] combination of the unique values generated, this article does not discuss the singleton mode of the implementation of a variety of ways and performance problems, casually get a way to achieve, the code is as follows:

Program.cs Program:

The code is as follows:
Using System;
Using System.Collections.Generic;
Using System.Linq;
Using System.Text;

Using System.Collections;
Using System.Xml;

Namespace ConsoleApplication4
{
Class Program
{
static void Main (string[] args)
{
Createid Createid = Createid.getinstance ();

Tests whether duplicates are generated
Console.WriteLine ("Singleton mode implementation, the unique value generated by the [0-9a-z] combination, as follows:");
ilist<string> list = new list<string> ();
for (int i = 1; I <= 1000000000; i++)
{
String struniquenum = Createid.createuniqueid ();
Console.WriteLine ("{0}\t{1}", List. Count, Struniquenum);
if (list. Contains (Struniquenum))
{
Console.WriteLine ("{0} value is duplicated", struniquenum);
Console.readkey ();
}

List. ADD (Struniquenum);

if (i% 200 = = 0)
{
Console.WriteLine ("No duplicates, press the ENTER key to look down");
Console.readkey ();
}
}

List. Clear ();
}
}

<summary>
Single-Instance mode implementation
Unique values are combined by [0-9a-z] and each generated ID cannot be duplicated
</summary>
public class Createid
{
private static Createid _instance;
private static readonly Object syncRoot = new Object ();
Private ehashtable hashtable = new ehashtable ();
private string _strxmlurl = String. Empty;

Private Createid ()
{
Hashtable. ADD ("0", "0");
Hashtable. ADD ("1", "1");
Hashtable. ADD ("2", "2");
Hashtable. ADD ("3", "3");
Hashtable. ADD ("4", "4");
Hashtable. ADD ("5", "5");
Hashtable. ADD ("6", "6");
Hashtable. ADD ("7", "7");
Hashtable. ADD ("8", "8");
Hashtable. ADD ("9", "9");
Hashtable. ADD ("Ten", "a");
Hashtable. ADD ("One", "B");
Hashtable. Add ("n", "C");
Hashtable. ADD ("+", "D");
Hashtable. ADD ("+", "E");
Hashtable. ADD ("All", "F");
Hashtable. ADD ("+", "G");
Hashtable. Add ("n", "H");
Hashtable. ADD ("+", "I");
Hashtable. ADD ("+", "J");
Hashtable. ADD ("A", "K");
Hashtable. ADD ("+", "L");
Hashtable. ADD ("A", "M");
Hashtable. ADD ("All", "n");
Hashtable. ADD ("+", "O");
Hashtable. ADD ("+", "P");
Hashtable. ADD ("+", "Q");
Hashtable. Add ("n", "R");
Hashtable. ADD ("+", "s");
Hashtable. ADD ("+", "T");
Hashtable. ADD ("V", "U");
Hashtable. ADD ("+", "V");
Hashtable. ADD ("+", "w");
Hashtable. Add ("×", "X");
Hashtable. ADD ("The", "Y");
Hashtable. ADD ("+", "Z");
_strxmlurl = System.IO.Path.GetFullPath (@ "). \.. \ ") +" Xmls\\record.xml ";

}

public static Createid getinstance ()
{
if (_instance = = null)
{
Lock (SyncRoot)
{
if (_instance = = null)
{
_instance = new Createid ();
}
}
}

return _instance;
}

<summary>
Create UniqueID
</summary>
<returns>UniqueID</returns>
public string Createuniqueid ()
{
Long _uniqueid = Getguidfromxml ();

Return convert10to36 (_uniqueid);
}

<summary>
Gets the UniqueID total record, that is, gets the ID of the number that is obtained
Update the number of UniqueID used for the next use
</summary>
<returns></returns>
Private Long Getguidfromxml ()
{
Long record = 0;
XmlDocument xmldoc = new XmlDocument ();
XmlDoc. Load (_strxmlurl);
XmlElement RootNode = xmldoc. DocumentElement;
The value of this number
Record = Convert.toint64 (rootnode["record"). InnerText);
The number of this time is +1 = = The next number of values
Rootnode["Record"]. InnerText = convert.tostring (record + 1);
XmlDoc. Save (_strxmlurl);

return record;
}

<summary>
10-in-turn 36-in system
</summary>
<param name= "INTNUM10" >10 binary number </param>
<returns></returns>
private string convert10to36 (long INTNUM10)
{
String strNum36 = String. Empty;
Long result = INTNUM10/36;
Long remain = intNum10% 36;
if (Hashtable. ContainsKey (remain. ToString ()))
STRNUM36 = Hashtable[remain. ToString ()]. ToString () + strNum36;
INTNUM10 = result;
while (INTNUM10/36! = 0)
{
result = INTNUM10/36;
remain = intNum10% 36;
if (Hashtable. ContainsKey (remain. ToString ()))
STRNUM36 = Hashtable[remain. ToString ()]. ToString () + strNum36;
INTNUM10 = result;
}
if (intNum10 > 0 && INTNUM10 < 36)
{
if (Hashtable. ContainsKey (Intnum10.tostring ()))
STRNUM36 = Hashtable[intnum10.tostring ()]. ToString () + strNum36;
}

return STRNUM36;
}

}

<summary>
Summary description for Ehashtable
</summary>
public class Ehashtable:hashtable
{
Private ArrayList list = new ArrayList ();
public override void Add (object key, Object value)
{
Base. ADD (key, value);
List. ADD (key);
}
public override void Clear ()
{
Base. Clear ();
List. Clear ();
}
public override void Remove (object key)
{
Base. Remove (key);
List. Remove (key);
}
public override ICollection Keys
{
Get
{
return list;
}
}
}

}

Xml:

The code is as follows:
<?xml version= "1.0" encoding= "Utf-8"?>
<root>
<record id= "Record" >1</record>
</root>

Second, the generation of GUIDs in JS, similar. NET Guid.NewGuid (), the code is as follows:

Copy the code code as follows:
function NewGuid () {//Method one:
var guid = "";
var n = (((1 + math.random ()) * 0x10000) | 0). toString (+). substring (1);
for (var i = 1; I <= 8; i++) {
GUID + = n;
}
return GUID;
}

function NewGuid () {//Method two:
var guid = "";
for (var i = 1; i <=; i++) {
var n = math.floor (Math.random () * 16.0). toString (16);
GUID + = n;
if ((i = = 8) | | (i = = 12) | | (i = = 16) | | (i = = 20))
GUID + = "-";
}
return GUID;
}

C. Generate the GUID in the SQL stored procedure, with the following code:

Copy the code code as follows:
-- =============================================
--AUTHOR:WANGWS
--Create date:2015-06-05
--Description: Generates a unique identity ID, a public stored procedure that can be set to call this stored procedure in another stored procedure to pass a different prefix
-- =============================================
ALTER PROCEDURE [dbo]. [Pro_createguid]
@Prefix NVARCHAR (10),
@outputV_guid NVARCHAR (+) OUTPUT
As
BEGIN
--SET NOCOUNT on added to prevent extra result sets from
--interfering with SELECT statements.
SET NOCOUNT on;

--Insert statements for procedure here
SET @outputV_guid = @Prefix + REPLACE (CAST (NEWID () as VARCHAR (36)), '-', ')
END

C # method Rollup for generating unique values