SQL: parse the first, middle and last name from a fullname field

Question

How do I parse the first, middle, and last name out of a fullname field with SQL?

I need to try to match up on names that are not a direct match on full name. I\'d

Answer 1

1. Get a sql regex function. Sample: http://msdn.microsoft.com/en-us/magazine/cc163473.aspx
2. Extract names using regular expressions.

I recommend Expresso for learnin/building/testing regular expressions. Old free version, new commercial version

Answer 2

Are you sure the Full Legal Name will always include First, Middle and Last? I know people that have only one name as Full Legal Name, and honestly I am not sure if that's their First or Last Name. :-) I also know people that have more than one Fisrt names in their legal name, but don't have a Middle name. And there are some people that have multiple Middle names.

Then there's also the order of the names in the Full Legal Name. As far as I know, in some Asian cultures the Last Name comes first in the Full Legal Name.

On a more practical note, you could split the Full Name on whitespace and threat the first token as First name and the last token (or the only token in case of only one name) as Last name. Though this assumes that the order will be always the same.

Answer 3

I would do this as an iterative process.

1) Dump the table to a flat file to work with.

2) Write a simple program to break up your Names using a space as separator where firsts token is the first name, if there are 3 token then token 2 is middle name and token 3 is last name. If there are 2 tokens then the second token is the last name. (Perl, Java, or C/C++, language doesn't matter)

3) Eyeball the results. Look for names that don't fit this rule.

4) Using that example, create a new rule to handle that exception...

5) Rinse and Repeat

Eventually you will get a program that fixes all your data.

Answer 4

Here is a self-contained example, with easily manipulated test data.

With this example, if you have a name with more than three parts, then all the "extra" stuff will get put in the LAST_NAME field. An exception is made for specific strings that are identified as "titles", such as "DR", "MRS", and "MR".

If the middle name is missing, then you just get FIRST_NAME and LAST_NAME (MIDDLE_NAME will be NULL).

You could smash it into a giant nested blob of SUBSTRINGs, but readability is hard enough as it is when you do this in SQL.

Edit-- Handle the following special cases:

1 - The NAME field is NULL

2 - The NAME field contains leading / trailing spaces

3 - The NAME field has > 1 consecutive space within the name

4 - The NAME field contains ONLY the first name

5 - Include the original full name in the final output as a separate column, for readability

6 - Handle a specific list of prefixes as a separate "title" column

SELECT
  FIRST_NAME.ORIGINAL_INPUT_DATA
 ,FIRST_NAME.TITLE
 ,FIRST_NAME.FIRST_NAME
 ,CASE WHEN 0 = CHARINDEX(' ',FIRST_NAME.REST_OF_NAME)
       THEN NULL  --no more spaces?  assume rest is the last name
       ELSE SUBSTRING(
                       FIRST_NAME.REST_OF_NAME
                      ,1
                      ,CHARINDEX(' ',FIRST_NAME.REST_OF_NAME)-1
                     )
       END AS MIDDLE_NAME
 ,SUBSTRING(
             FIRST_NAME.REST_OF_NAME
            ,1 + CHARINDEX(' ',FIRST_NAME.REST_OF_NAME)
            ,LEN(FIRST_NAME.REST_OF_NAME)
           ) AS LAST_NAME
FROM
  (  
  SELECT
    TITLE.TITLE
   ,CASE WHEN 0 = CHARINDEX(' ',TITLE.REST_OF_NAME)
         THEN TITLE.REST_OF_NAME --No space? return the whole thing
         ELSE SUBSTRING(
                         TITLE.REST_OF_NAME
                        ,1
                        ,CHARINDEX(' ',TITLE.REST_OF_NAME)-1
                       )
    END AS FIRST_NAME
   ,CASE WHEN 0 = CHARINDEX(' ',TITLE.REST_OF_NAME)  
         THEN NULL  --no spaces @ all?  then 1st name is all we have
         ELSE SUBSTRING(
                         TITLE.REST_OF_NAME
                        ,CHARINDEX(' ',TITLE.REST_OF_NAME)+1
                        ,LEN(TITLE.REST_OF_NAME)
                       )
    END AS REST_OF_NAME
   ,TITLE.ORIGINAL_INPUT_DATA
  FROM
    (   
    SELECT
      --if the first three characters are in this list,
      --then pull it as a "title".  otherwise return NULL for title.
      CASE WHEN SUBSTRING(TEST_DATA.FULL_NAME,1,3) IN ('MR ','MS ','DR ','MRS')
           THEN LTRIM(RTRIM(SUBSTRING(TEST_DATA.FULL_NAME,1,3)))
           ELSE NULL
           END AS TITLE
      --if you change the list, don't forget to change it here, too.
      --so much for the DRY prinicple...
     ,CASE WHEN SUBSTRING(TEST_DATA.FULL_NAME,1,3) IN ('MR ','MS ','DR ','MRS')
           THEN LTRIM(RTRIM(SUBSTRING(TEST_DATA.FULL_NAME,4,LEN(TEST_DATA.FULL_NAME))))
           ELSE LTRIM(RTRIM(TEST_DATA.FULL_NAME))
           END AS REST_OF_NAME
     ,TEST_DATA.ORIGINAL_INPUT_DATA
    FROM
      (
      SELECT
        --trim leading & trailing spaces before trying to process
        --disallow extra spaces *within* the name
        REPLACE(REPLACE(LTRIM(RTRIM(FULL_NAME)),'  ',' '),'  ',' ') AS FULL_NAME
       ,FULL_NAME AS ORIGINAL_INPUT_DATA
      FROM
        (
        --if you use this, then replace the following
        --block with your actual table
              SELECT 'GEORGE W BUSH' AS FULL_NAME
        UNION SELECT 'SUSAN B ANTHONY' AS FULL_NAME
        UNION SELECT 'ALEXANDER HAMILTON' AS FULL_NAME
        UNION SELECT 'OSAMA BIN LADEN JR' AS FULL_NAME
        UNION SELECT 'MARTIN J VAN BUREN SENIOR III' AS FULL_NAME
        UNION SELECT 'TOMMY' AS FULL_NAME
        UNION SELECT 'BILLY' AS FULL_NAME
        UNION SELECT NULL AS FULL_NAME
        UNION SELECT ' ' AS FULL_NAME
        UNION SELECT '    JOHN  JACOB     SMITH' AS FULL_NAME
        UNION SELECT ' DR  SANJAY       GUPTA' AS FULL_NAME
        UNION SELECT 'DR JOHN S HOPKINS' AS FULL_NAME
        UNION SELECT ' MRS  SUSAN ADAMS' AS FULL_NAME
        UNION SELECT ' MS AUGUSTA  ADA   KING ' AS FULL_NAME      
        ) RAW_DATA
      ) TEST_DATA
    ) TITLE
  ) FIRST_NAME

Answer 5

The work by @JosephStyons and @Digs is great! I used parts of their work to create a new function for SQL Server 2016 and newer. This one also handles suffixes, as well as prefixes.

CREATE FUNCTION [dbo].[NameParser]
(
    @name nvarchar(100)
)
RETURNS TABLE
AS
RETURN (

WITH prep AS (
    SELECT 
        original = @name,
        cleanName = REPLACE(REPLACE(REPLACE(REPLACE(LTRIM(RTRIM(@name)),'  ',' '),'  ',' '), '.', ''), ',', '')
)
SELECT
    prep.original,
    aux.prefix,
    firstName.firstName,
    middleName.middleName,
    lastName.lastName,
    aux.suffix
FROM
    prep
    CROSS APPLY (
        SELECT 
            prefix =
                CASE 
                    WHEN LEFT(prep.cleanName, 3) IN ('MR ', 'MS ', 'DR ', 'FR ')
                        THEN LEFT(prep.cleanName, 2)
                    WHEN LEFT(prep.cleanName, 4) IN ('MRS ', 'LRD ', 'SIR ')
                        THEN LEFT(prep.cleanName, 3)
                    WHEN LEFT(prep.cleanName, 5) IN ('LORD ', 'LADY ', 'MISS ', 'PROF ')
                        THEN LEFT(prep.cleanName, 4)
                    ELSE ''
                END,
            suffix =
                CASE 
                    WHEN RIGHT(prep.cleanName, 3) IN (' JR', ' SR', ' II', ' IV')
                        THEN RIGHT(prep.cleanName, 2)
                    WHEN RIGHT(prep.cleanName, 4) IN (' III', ' ESQ')
                        THEN RIGHT(prep.cleanName, 3)
                    ELSE ''
                END
    ) aux
    CROSS APPLY (
        SELECT
            baseName = LTRIM(RTRIM(SUBSTRING(prep.cleanName, LEN(aux.prefix) + 1, LEN(prep.cleanName) - LEN(aux.prefix) - LEN(aux.suffix)))),
            numParts = (SELECT COUNT(1) FROM STRING_SPLIT(LTRIM(RTRIM(SUBSTRING(prep.cleanName, LEN(aux.prefix) + 1, LEN(prep.cleanName) - LEN(aux.prefix) - LEN(aux.suffix)))), ' '))
    ) core
    CROSS APPLY (
        SELECT
            firstName = 
                CASE
                    WHEN core.numParts <= 1 THEN core.baseName
                    ELSE LEFT(core.baseName, CHARINDEX(' ', core.baseName, 1) - 1) 
                END

    ) firstName
    CROSS APPLY (
        SELECT
            remainder = 
                CASE
                    WHEN core.numParts <= 1 THEN ''
                    ELSE LTRIM(SUBSTRING(core.baseName, LEN(firstName.firstName) + 1, 999999))
                END
    ) work1
    CROSS APPLY (
        SELECT
            middleName = 
                CASE
                    WHEN core.numParts <= 2 THEN ''
                    ELSE LEFT(work1.remainder, CHARINDEX(' ', work1.remainder, 1) - 1) 
                END
    ) middleName
    CROSS APPLY (
        SELECT
            lastName = 
                CASE
                    WHEN core.numParts <= 1 THEN ''
                    ELSE LTRIM(SUBSTRING(work1.remainder, LEN(middleName.middleName) + 1, 999999))
                END
    ) lastName
)

GO

SELECT * FROM dbo.NameParser('Madonna')
SELECT * FROM dbo.NameParser('Will Smith')
SELECT * FROM dbo.NameParser('Neil Degrasse Tyson')
SELECT * FROM dbo.NameParser('Dr. Neil Degrasse Tyson')
SELECT * FROM dbo.NameParser('Mr. Hyde')
SELECT * FROM dbo.NameParser('Mrs. Thurston Howell, III')