Replace first occurrence of substring in a string in SQL

Question

I have to fetch data from a @temp table which has something like "or ccc or bbb or aaa" I want to replace the first occurrence into space to get something like this " ccc or bbb or aaa". I am trying stuff and replace but they don't seem to get me the desired result

What I have tried:

DECLARE @stringhere as varchar(500)

DECLARE @stringtofind as varchar(500)

set @stringhere='OR contains or cccc or  '

set @stringtofind='or'
select STUFF('OR contains or cccc or  ',PATINDEX('or', 'OR contains or cccc or  '),0 ,' ')

Answer 1

You can use a combination of STUFF and CHARINDEX to achieve what you want:

SELECT STUFF(col, CHARINDEX('substring', col), LEN('substring'), 'replacement')
FROM #temp

CHARINDEX('substring', col) will return the index of the first occurrence of 'substring' in the column. STUFF then replaces this occurrence with 'replacement' .

Answer 2

it seems you miss 2 % preceding and trailing to the target string

please try:

select STUFF(@stringhere, PATINDEX('%' + @stringtofind + '%', @stringhere), LEN(@stringtofind), ' ')

Answer 3

您可以执行CHARINDEX或PATINDEX ，如上所示，但我也建议添加COALESCE ，以防您的@stringtoFind未包含在您的@stringhere 。

SELECT COALESCE(STUFF(@stringhere, PATINDEX('%' + @stringtofind + '%', @stringhere), LEN(@stringtofind), ' '), @stringhere)

Answer 4

I had the same problem and made the same response as Tim Biegeleisen, but in a function:

CREATE FUNCTION DBO.FN_REPLACE_FIRST(@X NVARCHAR(MAX), @F NVARCHAR(MAX), @R NVARCHAR(MAX)) RETURNS NVARCHAR(MAX) AS BEGIN
RETURN STUFF(@X, CHARINDEX(@F, @X), LEN(@F), @R)
END

So I just call the function instead:

SELECT DBO.FN_REPLACE_FIRST('Text example', 'ex', 'eexx') --> Returns 'Teexxt example'

The explanation is the same