Replacing a string in a text field - sql

Question

I have a column in my database table which has lows of text and lows of rows. In the text, a url needs to be changed for every row. In each row the url can exist more than once.
Can I use the replace function to change all the urls in the text field in my database table without affecting the rest of the text in that same column?
Thanks

Answer 1

Use REPLACE()
UPDATE table SET text = REPLACE(text, 'from', 'to')
Make precise from: like with http://url_from.com/ to http://url_to.com/

Answer 2

Based on article posted at https://web.archive.org/web/20150521050102/http://sqlserver2000.databases.aspfaq.com:80/how-do-i-handle-replace-within-an-ntext-column-in-sql-server.html
I needed to write a find and replace for CHAR(146) ` in a text field. Above article for fort nText and the same solution for text worked with nText with the following changes:
- VARCHAR(32) from nVARCHAR(32)
- use #lenOldString = DATALENGTH(#oldString) instead of SET #lenOldString = DATALENGTH(#oldString)/2.
DECLARE
#TextPointer BINARY(16),
#TextIndex INT,
#oldString VARCHAR(32),
#newString VARCHAR(32),
#lenOldString INT,
#currentDataID INT;
SET #oldString = '’';
SET #newString = '''';
IF CHARINDEX(#oldString, #newString) > 0
BEGIN
PRINT 'Quitting to avoid infinite loop.';
END
ELSE
BEGIN
--Need the for nText fields
--SET #lenOldString = DATALENGTH(#oldString)/2
--Use this for text fields
SET #lenOldString = DATALENGTH(#oldString)
DECLARE irows CURSOR
LOCAL FORWARD_ONLY STATIC READ_ONLY FOR
SELECT
DataID
FROM
dbo.tbData
WHERE
PATINDEX('%'+#oldString+'%', TextData) > 0;
OPEN irows;
FETCH NEXT FROM irows INTO #currentDataID;
WHILE (##FETCH_STATUS = 0)
BEGIN
SELECT
#TextPointer = TEXTPTR(TextData),
#TextIndex = PATINDEX('%'+#oldString+'%', TextData)
FROM
dbo.tbData
WHERE
DataID = #currentDataID;
SELECT #TextPointer, #TextIndex
WHILE
(
SELECT
PATINDEX('%'+#oldString+'%', TextData)
FROM
dbo.tbData
WHERE
DataID = #currentDataID
) > 0
BEGIN
SELECT
#TextIndex = PATINDEX('%'+#oldString+'%', TextData)-1
FROM
dbo.tbData
WHERE
DataID = #currentDataID;
UPDATETEXT dbo.tbData.TextData #TextPointer #TextIndex #lenOldString #newString;
END
FETCH NEXT FROM irows INTO #currentDataID;
END
CLOSE irows;
DEALLOCATE irows;
END