How do i get the highest record from datatable

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I have below records in my datatable (in single column)

S00118-JR10-B-NO-R-JS-26
S00118-JR10-B-NO-R-JS-22
S00118-JR10-B-NO-R-JS-24
S00201-0110-B-NO-R-ST-16
S00201-0110-B-NO-R-ST-15
S00201-JRSR-B-RE-R-TS-20
S00118-0110-B-NO-R-JK-46
S00201-0104-M-NO-R-SH-11
S00118-0110-B-NO-R-JK-34

I want distinct record with higest number at the end as follows

S00118-JR10-B-NO-R-JS-26
S00201-0110-B-NO-R-ST-16
S00201-JRSR-B-RE-R-TS-20
S00118-0110-B-NO-R-JK-46
S00201-0104-M-NO-R-SH-11

Posted 2-Mar-16 23:25pm

Devraj Kapdi

Updated 3-Mar-16 21:13pm

v3

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dan!sh 3-Mar-16 5:42am

Is this one column?

Devraj Kapdi 3-Mar-16 5:45am

yes

dan!sh 3-Mar-16 5:49am

What is there in other columns? Update the question with entire table structure.

Devraj Kapdi 3-Mar-16 5:52am

the datatable containing only single column.

4 solutions

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OriginalGriff · Answer 1 · 2016-03-02T23:56:00

If they are all two digit, then try:

SQL

SELECT MAX(MyColumn) FROM MyTable
GROUP BY SUBSTRING(MyColumn, 1, 21)

If they aren't, then it becomes a PITA because the default sort order for strings is based on the difference between the first character pair that don't match - not a numeric value.

[edit]
Thinking about it, not that much of a PITA:

SQL

SELECT  Prefix + CAST(MAX(Val) AS NVARCHAR)  
FROM 
   (SELECT SUBSTRING(MyColumn, 1, 22) AS Prefix, CAST(SUBSTRING(MyColumn, 23, 9999) AS INT) AS Val FROM MyTable) a
GROUP BY Prefix

[/edit]

*dan!sh* · Answer 2 · 2016-03-03T00:17:00

Solution 2

You can do it like this:

C#

List<string> filtered = test.OrderByDescending(x => Convert.ToInt32(x.Substring(x.LastIndexOf("-") + 1))).GroupBy(x => x.Substring(0, x.LastIndexOf("-"))).Select(x => x.First()).ToList();

If this does not work for you, try fixing is yourself.

Posted 3-Mar-16 0:17am

dan!sh

Comments

Devraj Kapdi 3-Mar-16 7:00am

thank u d@nish it worked for me with little modification for datatable as...

List <datarow> filtered = dtOrderHistotyFinal.AsEnumerable().ToList().OrderByDescending(x => Convert.ToInt32(x["col1"].ToString().Substring(x["col1"].ToString().LastIndexOf("-") + 1))).GroupBy(x => x["col1"].ToString().Substring(0, x["col1"].ToString().LastIndexOf("-"))).Select(x => x.First()).ToList();

Camello01 · Answer 3 · 2016-03-03T12:16:00

Here is other way to made it

I create your table with that column.

SELECT Mycolumn FROM MyTable;

Mycolumn
S00118-JR10-B-NO-R-JS-26
S00118-JR10-B-NO-R-JS-22
S00118-JR10-B-NO-R-JS-24
S00201-0110-B-NO-R-ST-16
S00201-0110-B-NO-R-ST-15
S00201-JRSR-B-RE-R-TS-20
S00118-0110-B-NO-R-JK-46
S00201-0104-M-NO-R-SH-11
S00118-0110-B-NO-R-JK-34

And here is the conde I use to get your result requsted with a CTE.

WITH CTE(LEFTSTR, RIGHTSTR, Dupplicate)
AS
(SELECT DISTINCT
		LEFT(Mycolumn,LEN(Mycolumn)-(CHARINDEX('-',REVERSE(Mycolumn))-1))AS LEFTSTR,
		RIGHT(Mycolumn,(CHARINDEX('-',REVERSE(Mycolumn))-1))AS RIGHTSTR,
		ROW_NUMBER() OVER(PARTITION BY LEFT(Mycolumn,LEN(Mycolumn)-(CHARINDEX('-',REVERSE(Mycolumn))-1)) 
						  ORDER BY RIGHT(Mycolumn,(CHARINDEX('-',REVERSE(Mycolumn))-1))DESC)AS Dupplicate
FROM MyTable)

SELECT (LEFTSTR + RIGHTSTR)AS MyColumn  FROM CTE
WHERE Dupplicate = 1;

And Here is the result:

MyColumn
S00118-0110-B-NO-R-JK-46
S00118-JR10-B-NO-R-JS-26
S00201-0104-M-NO-R-SH-11
S00201-0110-B-NO-R-ST-16
S00201-JRSR-B-RE-R-TS-20

Maciej Los · Answer 4 · 2016-03-03T21:13:00

First of all: wrong approach! Why?

You have to work on data, not on string representation of data!

Assuming that each part of string (between [-]) represents some portion of data, you have to define class which can store that piece of data. For training purposes only i decided to write simple HelperClass with 2 properties: Header and Number. Header property is used to store string till the last [-] and Number property to store number.

C#

public class HelperClass
{
	private string header = string.Empty;
	private int nmb = 0;
	
	public string Header
	{
		get {return header;}
		set {header = value;}
	}
	
	public int Number
	{
		get {return nmb;}
		set {nmb = value;}
	}
	
	public override string ToString()
	{
		return header;
	}

}

How to use it?

C#

void Main()
{
	List<string> numbers = new List<string>()
							{
							"S00118-JR10-B-NO-R-JS-26",
							"S00118-JR10-B-NO-R-JS-22",
							"S00118-JR10-B-NO-R-JS-24",
							"S00201-0110-B-NO-R-ST-16",
							"S00201-0110-B-NO-R-ST-15",
							"S00201-JRSR-B-RE-R-TS-20",
							"S00118-0110-B-NO-R-JK-46",
							"S00201-0104-M-NO-R-SH-11",
							"S00118-0110-B-NO-R-JK-34"
							};
							
	var highestNumbers = numbers.Select(x=>new HelperClass
				{
					Header = x.Substring(0,22),
					Number = Convert.ToInt32(x.Substring(22,2))
				})
				.GroupBy(x=>x.Header)
				.Select(grp=> grp.Max(y=>y.Header) + grp.Max(y=>y.Number));
	foreach(var hn in highestNumbers)
	{
		Console.WriteLine("{0}", hn);
	}

}
</string></string>

Result:

S00118-JR10-B-NO-R-JS-26
S00201-0110-B-NO-R-ST-16
S00201-JRSR-B-RE-R-TS-20
S00118-0110-B-NO-R-JK-46
S00201-0104-M-NO-R-SH-11

How do i get the highest record from datatable

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