Using T-SQL, return nth delimited element from a string

Question

I have a need to create a function the will return nth element of a delimited string.

For a data migration project, I am converting JSON audit records stored in a S

Answer 1

How about:

CREATE FUNCTION dbo.NTH_ELEMENT (@Input NVARCHAR(MAX), @Delim CHAR = '-', @N INT = 0)
RETURNS NVARCHAR(MAX)
AS
BEGIN
RETURN (SELECT VALUE FROM STRING_SPLIT(@Input, @Delim) ORDER BY (SELECT NULL) OFFSET @N ROWS FETCH NEXT 1 ROW ONLY)
END

Answer 2

I would rather create a temp table with an identity column and fill it up with output from the SPLIT function.

  CREATE TABLE #tblVals(Id INT IDENTITY(1,1), Val NVARCHAR(100))
  INSERT INTO #tblVals (Val)
  SELECT [value] FROM STRING_SPLIT('Val1-Val3-Val2-Val5', '-')
  SELECT * FROM #tblVals

Now you can easily do something like below.

DECLARE @val2 NVARCHAR(100) = (SELECT TOP 1 Val FROM #tblVals WHERE Id = 2)

See the snapshot below:

Answer 3

I don't have enough reputation to comment, so I am adding an answer. Please adjust as appropriate.

I have a problem with Gary Kindel's answer for cases where there is nothing between the two delimiters

If you do select * from dbo.GetSplitString_CTE('abc^def^^ghi','^',3) you get ghi instead of an empty string

If you comment out the WHERE LEN([value]) > 0 line, you get the desired result

Answer 4

you can put this select into UFN. if you need you can customize it for specifying delimiter as well. in that case your ufn will have two input. number Nth and delimiter to use.

    DECLARE @tlist varchar(max)='10,20,30,40,50,60,70,80,90,100'
    DECLARE @i INT=1, @nth INT=3
    While len(@tlist) <> 0
    BEGIN
            IF @i=@nth
            BEGIN
              select Case when charindex(',',@tlist) <> 0 Then LEFT(@tlist,charindex(',',@tlist)-1)
                          Else @tlist
                    END
            END

              Select @tlist = Case when charindex(',',@tlist) <> 0 Then substring(@tlist,charindex(',',@tlist)+1,len(@tlist))
                          Else ''
                          END

            SELECT @i=@i+1
    END

Answer 5

In a rare moment of lunacy I just thought that split is far easier if we use XML to parse it out for us:

(Using the variables from @Gary Kindel's answer)

declare @xml xml
set @xml = '<split><el>' + replace(@list,@Delimiter,'</el><el>') + '</el></split>'

select
    el = split.el.value('.','varchar(max)')
from  @xml.nodes('/split/el') split(el))

This lists all elements of the string, split by the specified character.

We can use an xpath test to filter out empty values, and a further xpath test to restrict this to the element we're interested in. In full Gary's function becomes:

alter FUNCTION dbo.GetSplitString_CTE
(
   @List       VARCHAR(MAX),
   @Delimiter  VARCHAR(255),
   @ElementNumber int
)
RETURNS VARCHAR(max)
AS
BEGIN
       -- escape any XML https://dba.stackexchange.com/a/143140/65992  
       set @list = convert(VARCHAR(MAX),(select @list for xml path(''), type));

       declare @xml xml
       set @xml = '<split><el>' + replace(@list,@Delimiter,'</el><el>') + '</el></split>'

       declare @ret varchar(max)
       set @ret = (select
              el = split.el.value('.','varchar(max)')
       from  @xml.nodes('/split/el[string-length(.)>0][position() = sql:variable("@elementnumber")]') split(el))

       return @ret

END