Getting the middle name from a full name field - sql

Question

So, I've got functions to get the first and last names, like so:
create function udf_get_first_name (#string nvarchar(100))
returns nvarchar(50)
as
begin
declare #first_name nvarchar(50)
set #string = ltrim(#string)
set #string = rtrim(#string)
if dbo.udf_get_number_of_spaces(#string) > 0
set #first_name = left(#string, charindex(' ',#string) -1)
else
set #first_name = #string
return #first_name
end
create function udf_get_last_name (#string nvarchar(100))
returns nvarchar(50)
as
begin
set #string = ltrim(#string)
set #string = rtrim(#string)
if dbo.udf_get_number_of_spaces (#string) > 0
begin
set #string = reverse(#string)
set #string = left(#string, charindex(' ', #string) -1)
set #string = reverse(#string)
end
return #string
end
I need to be able to get the middle name, and just can't wrap my head around what I've been reading through my searching so far. Not sure if I'm just being dumb or not.
I also need to be able to sort a name formatted as L/M/F, into the proper columns as well, which I'm having an even harder time with.
Edit: Not all the records have middle names.

Answer 1

You can use the following solution, using a function to get a part of the name or the fullname in a specified format:
--
-- function to get a part of a fullname or to reformat the fullname.
-- #fullname - the fullname to get the part from or to reformat.
-- #format - the format of the output using F (firstname), M (middlename) and L (lastname).
-- the function returns the fullname in specified format or NULL if input is not valid
-- or the part of name is empty.
--
CREATE FUNCTION GetNamePart(#fullname VARCHAR(200), #format VARCHAR(30))
RETURNS VARCHAR(200)
AS
BEGIN
-- replace multiple spaces of the fullname and trim the result.
SET #fullname = LTRIM(RTRIM(REPLACE(REPLACE(REPLACE(#fullname, ' ', '<>'), '><', ''), '<>', ' ')))
-- get the different name parts (firstname, middlename and lastname) of the fullname.
DECLARE #first_name VARCHAR(100)
SET #first_name = LTRIM(RTRIM(LEFT(#fullname, CHARINDEX(' ', #fullname))))
DECLARE #last_name VARCHAR(100)
SET #last_name = LTRIM(RTRIM(RIGHT(#fullname, CHARINDEX(' ', REVERSE(#fullname)))))
DECLARE #middle_name VARCHAR(100)
SET #middle_name = LTRIM(RTRIM(SUBSTRING(#fullname, LEN(#first_name) + 1, LEN(#fullname) - LEN(#first_name) - LEN(#last_name))))
-- init the formatted name of the fullname.
DECLARE #formatted_name VARCHAR(100)
-- return only the formatted name if format string is valid.
IF PATINDEX('%[^LMF]%', UPPER(#format)) > 0
SET #formatted_name = ''
ELSE
BEGIN
SET #format = REPLACE(REPLACE(REPLACE(#format, 'M', '##M##'), 'L', '##L##'), 'F', '##F##')
SET #formatted_name = LTRIM(RTRIM(REPLACE(REPLACE(REPLACE(UPPER(#format), '##F##', #first_name + ' '), '##M##', #middle_name + ' '), '##L##', #last_name + ' ')))
END
-- check the input (#fullname) for valid value (firstname, lastname or firstname, middlename, lastname).
IF PATINDEX('%_ %_% _%', #fullname) = 0 AND PATINDEX('%_ _%', #fullname) = 0
SET #formatted_name = ''
-- return the new formatted name and replace multiple spaces.
RETURN NULLIF(REPLACE(REPLACE(REPLACE(#formatted_name, ' ', '<>'), '><', ''), '<>', ' '), '')
END
This function GetNamePart is using two parameters (#fullname and #format). The first parameter #fullname is the fullname containing the firstname, lastname and if available the middlename. The second parameter is defining the output format of the name. You can use the letters F (firstname), M (middlename) and L (lastname) to define the format of the output.
So you can use the function GetNamePart to get the middlename of the fullname:
SELECT dbo.GetNamePart(fullname, 'M') FROM table_name
... or to reformat the fullname like this:
SELECT dbo.GetNamePart(fullname, 'LMF') FROM table_name
demo on dbfiddle.uk (demo and test cases)
But you can also use a SELECT query to get the various parts of the name without a function:
SELECT
LTRIM(RTRIM(LEFT(fullname, CHARINDEX(' ', fullname)))) AS first_name,
LTRIM(RTRIM(RIGHT(fullname, CHARINDEX(' ', REVERSE(fullname))))) AS last_name,
LTRIM(RTRIM(CASE WHEN PATINDEX('%_ %_% _%', fullname) > 0 THEN SUBSTRING(fullname, CHARINDEX(' ', fullname) + 1, (CHARINDEX(' ', fullname, CHARINDEX(' ', fullname)+1)-(CHARINDEX(' ', fullname) + 1))) ELSE '' END)) AS middle_name
FROM table_name
demo on dbfiddle.uk

Answer 2

Similar to Sebastian Brosch's answer. I also added the TRIM function after I saw his answer. In this query, it's not necessary. But it's something nice to have. For example, if the user added multiple spaces by mistake, this will remove that.
There might be a better or simpler way to get first, middle and last name. But this is the way I come up with at the moment.
CREATE FUNCTION dbo.SplitFullName(
#FullName NVARCHAR(MAX),
#Format NVARCHAR(MAX)
)
RETURNS NVARCHAR(MAX)
AS
BEGIN
DECLARE #FN NVARCHAR(MAX);
DECLARE #MN NVARCHAR(MAX);
DECLARE #LN NVARCHAR(MAX);
DECLARE #RV NVARCHAR(MAX);
SET #FN = RTRIM(LTRIM(SUBSTRING(#FullName,0, CHARINDEX(' ',#FullName))));
SET #MN = RTRIM(LTRIM(SUBSTRING(#FullName, CHARINDEX(' ',#FullName) + 1 , LEN(#FullName) - (CHARINDEX(' ',#FullName) + CHARINDEX(' ',REVERSE(#FullName)))+1)));
SET #LN = RTRIM(LTRIM(REVERSE(SUBSTRING(REVERSE(#FullName),0, CHARINDEX(' ',REVERSE(#FullName))))));
IF (#Format='FN')
SET #RV = CASE WHEN LEN(#FN) = 0 THEN NULL ELSE #FN END;
ELSE IF (#Format='MN')
SET #RV = CASE WHEN LEN(#MN) = 0 THEN NULL ELSE #MN END;
ELSE IF (#Format='LN')
SET #RV = CASE WHEN LEN(#LN) = 0 THEN NULL ELSE #LN END;;
ELSE
SET #RV = CONCAT(#LN, ' ', CASE WHEN LEN(#MN) = 0 THEN NULL ELSE CONCAT(#MN , ' ') END, #FN);
RETURN #RV;
END;
Example 01
SELECT dbo.SplitFullName('Antonio P. Green', 'FN') AS FN,
dbo.SplitFullName('Antonio P. Green', 'MN') AS MN,
dbo.SplitFullName('Antonio P. Green', 'LN') AS LN,
dbo.SplitFullName('Antonio P. Green', 'LMF') AS LMF;
+---------+----+-------+------------------+
| FN | MN | LN | LMF |
+---------+----+-------+------------------+
| Antonio | P. | Green | Green P. Antonio |
+---------+----+-------+------------------+
Example 02
select dbo.SplitFullName('Cindy Bertha Collier Sproles', 'FN') AS FN,
dbo.SplitFullName('Cindy Bertha Collier Sproles', 'MN') AS MN,
dbo.SplitFullName('Cindy Bertha Collier Sproles', 'LN') AS LN,
dbo.SplitFullName('Cindy Bertha Collier Sproles', 'LMF') AS LMF;
+-------+----------------+---------+------------------------------+
| FN | MN | LN | LMF |
+-------+----------------+---------+------------------------------+
| Cindy | Bertha Collier | Sproles | Sproles Bertha Collier Cindy |
+-------+----------------+---------+------------------------------+
Example 03
SELECT dbo.SplitFullName('Tristan Jackson', 'FN') AS FN,
dbo.SplitFullName('Tristan Jackson', 'MN') AS MN,
dbo.SplitFullName('Tristan Jackson', 'LN') AS LN,
dbo.SplitFullName('Tristan Jackson', 'LMF') AS LMF;
+---------+------+---------+-----------------+
| FN | MN | LN | LMF |
+---------+------+---------+-----------------+
| Tristan | NULL | Jackson | Jackson Tristan |
+---------+------+---------+-----------------+

Answer 3

You can handle this using Multiple comma separated CTE.
declare #str nvarchar(max) ='kareena kapoor khan';
with
t0 AS (select charindex(' ',#str) pos, #str name ),
t1 AS (select charindex(' ',#str,pos+1)pos,#str name from t0)
select substring(t0.name,0,t0.pos) "firstName",
substring(t0.name,t0.pos+1,(t1.pos-t0.pos)) "MiddleName",
substring(t0.name,t1.pos+1,(len(t0.name)- t1.pos)) "Lastname"
from t0
inner join t1 on t0. name= t1.name
output
|firstName | MiddleName |Lastname
|kareena | kapoor |khan
Also, Instead of creating 3 function for first name , middle name and last name you can just create a single function and pass parameter as #namepart.

Answer 4

The future is start as sql-server 2016:
use STRING_SPLIT function
Use Northwind
Go
SELECT ProductID, value
FROM Products
CROSS APPLY STRING_SPLIT(ProductName, ' ');
by this query you can split names... then use by Row() function you can choose middle name.
STRING_SPLIT requires the compatibility level to be at least 130. When the level is less than 130, SQL Server is unable to find the STRING_SPLIT function.

Answer 5

Select Ltrim(SUBSTRING(name,CharIndex(' ',name),
CAse When (CHARINDEX(' ',name,CHARINDEX(' ',name)+1)-CHARINDEX(' ',name))<=0 then 0
else CHARINDEX(' ',name,CHARINDEX(' ',name)+1)-CHARINDEX(' ',name) end )) as MiddleName
From TableName