Remove string from SQL column - sql

Question

I have a TEXT datatype field called "XMLText" in SQL Server 2012. What I'd like to do is remove any SageID fields. So this long string field contains something that looks like this:
<pair n="priorinstitution2" v="Yale School of Medicine" />
<pair n="priorinstitution3" v="" />
<pair n="sageid" v="20668528" />
<pair n="priorinstitution1" v="University of Chicago" />
What I'd like to do is remove everything for the SageID tag so that the final result is this:
<pair n="priorinstitution2" v="Yale School of Medicine" />
<pair n="priorinstitution3" v="" />
<pair n="priorinstitution1" v="University of Chicago" />
Obviously, it's not in a fixed position in the field and the v= could be any numbers or length. What's the SQL string manipulation to do this?

Answer 1

TEXT is deprecated. Store your XML chunks as XML or NVARCHAR(MAX).
You can use xml.modify and delete to remove multiple occurences at once:
CREATE TABLE #tab(id INT, col TEXT);
INSERT INTO #tab(id, col)
VALUES
(1, '<pair n="priorinstitution2" v="Yale School of Medicine" />
<pair n="priorinstitution3" v="" />
<pair n="sageid" v="20668528" />
<pair n="priorinstitution1" v="University of Chicago" />')
,(2, '<pair n="sageid" v="2" y="adsadasdasd"/>
<pair n="priorinstitution2" v="Yale School of Medicine" />
<pair n="priorinstitution3" v="" />
<pair n="sageid" v="20668528" />
<pair n="priorinstitution1" v="University of Chicago" />
<pair n="sageid" v="2066852832421432" z="aaaa" />');
SELECT *, xml_col = CAST(col AS XML)
INTO #temp
FROM #tab;
UPDATE #temp
SET xml_col.modify('delete /pair[#n="sageid"]');
UPDATE t1
SET col = CAST(t2.xml_col AS NVARCHAR(MAX))
FROM #tab t1
JOIN #temp t2
ON t1.id = t2.id;
SELECT *
FROM #tab;
LiveDemo
Keep in mind that your XML data is not well-formed (no root element).
EDIT:
If your XML Text has different structure and you want to find all pair element with attribute n="sageid" use:
UPDATE #temp
SET xml_col.modify('delete //pair[#n="sageid"]');
LiveDemo2

Answer 2

Not a great solution but to find positions of start and end of tag and replace it with a blank string
UPDATE YourTable
SET yourColumn = REPLACE(yourColumn, SUBSTRING(yourColumn, CHARINDEX('<pair n="sageid"', yourColumn), CHARINDEX('/>', yourColumn, CHARINDEX('<pair n="sageid"', yourColumn)) - CHARINDEX('<pair n="sageid"', yourColumn) + 2), '')
Adding below script for debugging
DECLARE #str AS VARCHAR(255) = '<pair n="priorinstitution2" v="Yale School of Medicine" /><pair n="priorinstitution3" v="" /><pair n="sageid" v="20668528" /><pair n="priorinstitution1" v="University of Chicago" />'
SELECT REPLACE(#str, SUBSTRING(#str, CHARINDEX('<pair n="sageid"', #str), CHARINDEX('/>', #str, CHARINDEX('<pair n="sageid"', #str)) - CHARINDEX('<pair n="sageid"', #str) + 2), '')