In SQL Server 2016 finally they have introduced Split string function : STRING_SPLIT

Parameters: It accepts two parameters

String:

Is an expression of any character type (i.e. nvarchar, varchar, nchar or char).

separator :

Is a single character expression of any character type (e.g. nvarchar(1), varchar(1), nchar(1) or char(1)) that is used as separator for concatenated strings.

Note: You should always check if the expression is a non-empty string.

Example:

Select Value
From STRING_SPLIT('a|b|c','|')

In above example

String    : 'a|b|c'
separator : '|'

Result :

+-----+
|Value|
+-----+
|a    |
+-----+
|b    |
+-----+
|c    |
+-----+

If it's an empty string:

SELECT value
FROM STRING_SPLIT('',',')

Result :

  +-----+
  |Value|
  +-----+
1 |     |
  +-----+

You can avoid the above situation by adding a WHERE clause

SELECT value
FROM STRING_SPLIT('',',')
WHERE LTRIM(RTRIM(value))<>''

Since there is no STRING_SPLIT function we need to use XML hack to split the string into rows:

Example:

SELECT split.a.value('.', 'VARCHAR(100)') AS Value 
FROM   (SELECT Cast ('<M>' + Replace('A|B|C', '|', '</M><M>')+ '</M>' AS XML) AS Data) AS A 
       CROSS apply data.nodes ('/M') AS Split(a); 

Result:

+-----+
|Value|
+-----+
|A    |
+-----+
|B    |
+-----+
|C    |
+-----+

Declare @userList Table(UserKey VARCHAR(60))
Insert into @userList values ('bill'),('jcom'),('others')
--Declared a table variable and insert 3 records

Declare @text XML
Select  @text = (
        select UserKey  from @userList for XML Path('user'), root('group')
) 
--Set the XML value from Table 

Select @text

--View the variable value
XML: \<group>\<user>\<UserKey>bill\</UserKey>\</user>\<user>\<UserKey>jcom\</UserKey>\</user>\<user>\<UserKey>others\</UserKey>\</user>\</group>