Parse a varchar column containing XML like data into row wise - sql

Question

i have a column in table which contain data like XML,i would like to get data in rows.
My table data as-
select printDataColumn from Mytable
It returns value-
<PrintData>
<Line1>.MERCHANT ID: *****4005</Line1>
<Line2>.CLERK ID: ADMIN</Line2>
<Line3>.</Line3>
<Line4>. VOID SALE</Line4>
<Line5>.</Line5>
<Line6>.VISA ************0006</Line6>
<Line7>.ENTRY METHOD: SWIPED</Line7>
<Line8>.DATE: 03/05/2019 TIME: 16:57:20</Line8>
<Line9>.</Line9>
<Line10>.INVOICE: 1551785225020</Line10>
<Line11>.REFERENCE: 1008</Line11>
<Line12>.AUTH CODE: 08354A</Line12>
<Line13>.</Line13>
<Line14>.AMOUNT USD$ 1.14</Line14>
<Line15>. ==========</Line15>
<Line16>.TOTAL USD$ 1.14</Line16>
<Line17>.</Line17>
<Line18>. APPROVED - THANK YOU</Line18>
<Line19>.</Line19>
<Line20>.I AGREE TO PAY THE ABOVE TOTAL AMOUNT</Line20>
<Line21>.ACCORDING TO CARD ISSUER AGREEMENT</Line21>
<Line22>.(MERCHANT AGREEMENT IF CREDIT VOUCHER)</Line22>
<Line23>.</Line23>
<Line24>.</Line24>
<Line25>.</Line25>
<Line26>.x_______________________________________</Line26>
<Line27>. Merchant Signature</Line27>
<Line28>.</Line28>
</PrintData>
but i want to use this information in another way like that
MERCHANT ID: *****4005
CLERK ID: ADMIN
SALE
AMEX ***********1006
ENTRY METHOD: CHIP
DATE: 03/07/2019 TIME: 14:37:23
INVOICE: 1551949638173
REFERENCE: 1005
AUTH CODE: 040749. . . . .and so on.
any help is appreciable.

Answer 1

Besides the fact, that it always is a good idea to use the appropriate type to store your data, you can use a cast on the fly to use your xml-like-data with XML methods:
DECLARE #tbl TABLE(ID INT IDENTITY,PrintData VARCHAR(4000));
INSERT INTO #tbl VALUES
('<PrintData>
<Line1>.MERCHANT ID: *****4005</Line1>
<Line2>.CLERK ID: ADMIN</Line2>
<Line3>.</Line3>
<Line4>. VOID SALE</Line4>
<!-- more lines -->
</PrintData>');
SELECT t.ID
,A.Casted.value(N'(/PrintData/Line1/text())[1]','nvarchar(max)') AS Line1
FROM #tbl t
CROSS APPLY(SELECT CAST(t.PrintData AS XML)) A(Casted);
In this case I use CROSS APPLY to add a column A.Casted to the result set, which is a row-wise casted XML.
This will break, in cases of invalid XML (of course). You might try TRY_CAST instead. This would return NULL, but will hide data errors...
Some more background
The cast to XML is a rather expensive operation. Doing this whenever you want to read out of your data is some heavy load for your server. Furthermore, using VARCHAR is prone to two major errors:
If there are foreign characters you might get question marks
If the XML is not valid, you will not see it - until you use it.
If possible, try to change the table's design to use native XML.
And one more hint
It is a bad approach to name-number elements (same for columns). Instead of <Line1><Line2><Line3> better use <Line nr="1"><Line nr="2"><Line nr="3">...