Extract the first word of a string in a SQL Server query - tsql

Question

What's the best way to extract the first word of a string in sql server query?

Answer 1

SELECT CASE CHARINDEX(' ', #Foo, 1)
WHEN 0 THEN #Foo -- empty or single word
ELSE SUBSTRING(#Foo, 1, CHARINDEX(' ', #Foo, 1) - 1) -- multi-word
END
You could perhaps use this in a UDF:
CREATE FUNCTION [dbo].[FirstWord] (#value varchar(max))
RETURNS varchar(max)
AS
BEGIN
RETURN CASE CHARINDEX(' ', #value, 1)
WHEN 0 THEN #value
ELSE SUBSTRING(#value, 1, CHARINDEX(' ', #value, 1) - 1) END
END
GO -- test:
SELECT dbo.FirstWord(NULL)
SELECT dbo.FirstWord('')
SELECT dbo.FirstWord('abc')
SELECT dbo.FirstWord('abc def')
SELECT dbo.FirstWord('abc def ghi')

Answer 2

I wanted to do something like this without making a separate function, and came up with this simple one-line approach:
DECLARE #test NVARCHAR(255)
SET #test = 'First Second'
SELECT SUBSTRING(#test,1,(CHARINDEX(' ',#test + ' ')-1))
This would return the result "First"
It's short, just not as robust, as it assumes your string doesn't start with a space. It will handle one-word inputs, multi-word inputs, and empty string inputs.

Answer 3

Enhancement of Ben Brandt's answer to compensate even if the string starts with space by applying LTRIM(). Tried to edit his answer but rejected, so I am now posting it here separately.
DECLARE #test NVARCHAR(255)
SET #test = 'First Second'
SELECT SUBSTRING(LTRIM(#test),1,(CHARINDEX(' ',LTRIM(#test) + ' ')-1))

Answer 4

Adding the following before the RETURN statement would solve for the cases where a leading space was included in the field:
SET #Value = LTRIM(RTRIM(#Value))

Answer 5

Marc's answer got me most of the way to what I needed, but I had to go with patIndex rather than charIndex because sometimes characters other than spaces mark the ends of my data's words. Here I'm using '%[ /-]%' to look for space, slash, or dash.
Select race_id, race_description
, Case patIndex ('%[ /-]%', LTrim (race_description))
When 0 Then LTrim (race_description)
Else substring (LTrim (race_description), 1, patIndex ('%[ /-]%', LTrim (race_description)) - 1)
End race_abbreviation
from tbl_races
Results...
race_id race_description race_abbreviation
------- ------------------------- -----------------
1 White White
2 Black or African American Black
3 Hispanic/Latino Hispanic
Caveat: this is for a small data set (US federal race reporting categories); I don't know what would happen to performance when scaled up to huge numbers.

Answer 6

DECLARE #string NVARCHAR(50)
SET #string = 'CUT STRING'
SELECT LEFT(#string,(PATINDEX('% %',#string)))

Answer 7

Extract the first word from the indicated field:
SELECT SUBSTRING(field1, 1, CHARINDEX(' ', field1)) FROM table1;
Extract the second and successive words from the indicated field:
SELECT SUBSTRING(field1, CHARINDEX(' ', field1)+1, LEN (field1)-CHARINDEX(' ', field1)) FROM table1;

Answer 8

A slight tweak to the function returns the next word from a start point in the entry
CREATE FUNCTION [dbo].[GetWord]
(
#value varchar(max)
, #startLocation int
)
RETURNS varchar(max)
AS
BEGIN
SET #value = LTRIM(RTRIM(#Value))
SELECT #startLocation =
CASE
WHEN #startLocation > Len(#value) THEN LEN(#value)
ELSE #startLocation
END
SELECT #value =
CASE
WHEN #startLocation > 1
THEN LTRIM(RTRIM(RIGHT(#value, LEN(#value) - #startLocation)))
ELSE #value
END
RETURN CASE CHARINDEX(' ', #value, 1)
WHEN 0 THEN #value
ELSE SUBSTRING(#value, 1, CHARINDEX(' ', #value, 1) - 1)
END
END
GO
SELECT dbo.GetWord(NULL, 1)
SELECT dbo.GetWord('', 1)
SELECT dbo.GetWord('abc', 1)
SELECT dbo.GetWord('abc def', 4)
SELECT dbo.GetWord('abc def ghi', 20)

Answer 9

Try This:
Select race_id, race_description
, Case patIndex ('%[ /-]%', LTrim (race_description))
When 0 Then LTrim (race_description)
Else substring (LTrim (race_description), 1, patIndex ('%[ /-]%', LTrim (race_description)) - 1)
End race_abbreviation
from tbl_races