Get a particular string from an expression in a column in T-SQL - sql

Question

I have a column in my SQL Server database table which contains '|' (pipe) separated values.
Example:
'FirstName |testname| lastName | lastname | roll |ee097765 | 100 | end'
'FirstName |testname1| lastName | lastname1 | roll2 |ee0977652 | 1100 | end'.
I want to extract the marks only using T-SQL, where my output column will have only marks i.e. 100 only or 1100 subsequently. In Oracle we can use the
SUBSTRING_INDEX
function, but the same is not available in T-SQL.
Can anyone point me how to do this?
SUBSTRING_INDEX(SUBSTRING_INDEX(field, '|', 3), '|', -1)

Answer 1

declare #TEST table(val nvarchar(1000))
insert into #TEST
values ('FirstName |testname| lastName | lastname | roll |ee097765 | 100 | end'),
('FirstName |testname1| lastName | lastname1 | roll2 |ee0977652 | 1100 | end')
SELECT Value
FROM #TEST CROSS APPLY
Split(val,'|')
WHERE ISNUMERIC(Value) = 1
You just have to use a generic split function you'll find : https://codereview.stackexchange.com/questions/15125/sql-server-split-function

Answer 2

You could use SQLCLR function. There are some caveats in applying it to SQL Server. Anyway, here's one of the variants to find required values:
public partial class UserDefinedFunctions
{
[SqlFunction]
public static SqlString GetMarkPosition(SqlString sqlString)
{
// Assume there will be no result,
// so initialize return value to null string.
SqlString retVal = SqlString.Null;
// Extract C# string
string input = sqlString.Value;
// I use Regex Split method rather array Split method,
// since Regexe method handles spaces in elegant way.
string pattern = #"\s*\|\s*";
// Get array of values
string[] split = Regex.Split(input, pattern);
// The logic is the following:
// First, we find the marker's position in list.
// The sought value is one index less.
// This process is repeated for each marker.
// If no match is found for any marker,
// the function will just return empty string,
// as we initialized retVal variable.
foreach (string marker in new[] { "100", "1100" })
{
var list = new List<string>(split);
int index = list.IndexOf(marker);
if (index > 0)
{
retVal = new SqlString(list[index - 1]);
break;
}
}
return retVal;
}
}
In order to create this function, there are several steps you need to do.
If you're using SQL Server 2017, the security model has been changed (read, for example here and here), so Visual Studio won't help you in creating assembly on SQL Server's side - you'll have to do it manually.