मुझे कुछ साबुन खोजने जाना है, लेकिन आपकी आवश्यकताओं को देखते हुए, यह एक उदाहरण है कि वांछित प्रतिस्थापन कैसे प्राप्त किया जाए।
-- This will probably not perform terribly well for a number of
-- reasons, not the least of which we are doing lots of string manipulation
-- within tsql.
-- Much of this query nonsense could be consolidated into fewer queries
-- but given the dearth of information, I chose to build out the solution
-- in a tumbling data anti-pattern
;
WITH SAMPLE_DATA AS
(
-- gin up some demo data
-- with random spacing and ids to make valid test cases
select '<td class="m92_t_col5" id="preis_0">xx</td>' AS html
union all select '<td id="preis_2" class="m29_t_col5">no fix req</td>'
union all select '<td id="preis_49" class="m29_t_col5">no fix req</td>'
union all select '<td class="m93_t_col50" id="preis_3">xy</td>'
union all select '<td class="m95_t_col5" style="fuzzy" id="preis_5">xz</td>'
union all select '<td id="preis_8" class="m29_t_col5">no fix req</td>'
)
, ORDINALS AS
(
-- Find the starting position of the keywords
SELECT SD.*
, CHARINDEX('class=', SD.html, 0) AS class_ordinal
, CHARINDEX('id=', SD.html, 0) AS id_ordinal
-- You will really need something in here to keep stuff straight
-- otherwise when we bring it all back together, it'll be wrong
, ROW_NUMBER() OVER (ORDER BY (SELECT 1)) AS original_sequence
FROM SAMPLE_DATA SD
)
, NEEDS_MODIFIED AS
(
-- identify the rows that need modified
-- and use the ordinals in previous query to find the close position
SELECT
O.*
, CHARINDEX('"', O.html, O.class_ordinal+7) + 1 AS class_ordinal_end_quote
, CHARINDEX('"', O.html, O.id_ordinal+4) + 1 AS id_ordinal_end_quote
FROM
ORDINALS O
WHERE
O.id_ordinal > O.class_ordinal
)
, FIND_PARTS AS
(
-- strip out the parts
SELECT
NM.*
, SUBSTRING(NM.html, class_ordinal, class_ordinal_end_quote - class_ordinal) AS class
, SUBSTRING(NM.html, id_ordinal, id_ordinal_end_quote - id_ordinal) AS id
FROM
NEEDS_MODIFIED NM
)
, DONE AS
(
SELECT
-- This is the heart of the matter
-- having identified the correct text values for class and id
-- we will now perform a triple replace
-- Replace 1 is swapping the class text with somthing that should not exist in source
-- Replace 2 replaces the id text with our class text
-- Replace 3 removes our placeholder value with id
REPLACE(REPLACE(REPLACE(FP.html, FP.class, '~~|~'), FP.id, FP.class), '~~|~', FP.id) AS html
, FP.original_sequence
FROM
FIND_PARTS FP
UNION ALL
SELECT
O.html
, O.original_sequence
FROM
ORDINALS O
WHERE
O.id_ordinal < O.class_ordinal
)
SELECT
D.html
FROM
DONE D
ORDER BY
D.original_sequence
इनपुट
<td class="m92_t_col5" id="preis_0">xx</td>
<td id="preis_2" class="m29_t_col5">no fix req</td>
<td id="preis_49" class="m29_t_col5">no fix req</td>
<td class="m93_t_col50" id="preis_3">xy</td>
<td class="m95_t_col5" style="fuzzy" id="preis_5">xz</td>
<td id="preis_8" class="m29_t_col5">no fix req</td>
आउटपुट
<td id="preis_0" class="m92_t_col5">xx</td>
<td id="preis_2" class="m29_t_col5">no fix req</td>
<td id="preis_49" class="m29_t_col5">no fix req</td>
<td id="preis_3" class="m93_t_col50">xy</td>
<td id="preis_5" style="fuzzy" class="m95_t_col5">xz</td>
<td id="preis_8" class="m29_t_col5">no fix req</td>
कुछ सोचने के बाद, हो सकता है कि आप इसे एक अदिश फलन के रूप में पूछने का प्रयास कर रहे हों। इसका शायद और भी खराब प्रदर्शन होगा लेकिन यह समस्या का समाधान करता है।
-- Same logic as above, now in function form
CREATE FUNCTION dbo.ClassIdSwap
(
@input varchar(max)
)
RETURNS varchar(max)
AS
BEGIN
DECLARE
@class_ordinal int
, @class_text varchar(max)
, @class_ordinal_end_quote int
, @id_ordinal int
, @id_text varchar(max)
, @id_ordinal_end_quote int
, @out_html varchar(max)
SELECT
@class_ordinal = CHARINDEX('class=', @input, 0)
, @id_ordinal = CHARINDEX('id=', @input, 0)
SELECT
@class_ordinal_end_quote = CHARINDEX('"', @input, @class_ordinal+7) + 1
, @id_ordinal_end_quote = CHARINDEX('"', @input, @id_ordinal+4) + 1
-- bail out early
IF (@id_ordinal < @class_ordinal)
BEGIN
RETURN @input
END
SELECT
@class_text = SUBSTRING(@input, @class_ordinal, @class_ordinal_end_quote - @class_ordinal)
, @id_text = SUBSTRING(@input, @id_ordinal, @id_ordinal_end_quote - @id_ordinal)
RETURN (REPLACE(REPLACE(REPLACE(@input, @class_text, '~~|~'), @id_text, @class_text), '~~|~', @id_text))
END
उपयोग
;
WITH SAMPLE_DATA AS
(
-- gin up some demo data
-- with random spacing and ids to make valid test cases
select '<td class="m92_t_col5" id="preis_0">xx</td>' AS html
union all select '<td id="preis_2" class="m29_t_col5">no fix req</td>'
union all select '<td id="preis_49" class="m29_t_col5">no fix req</td>'
union all select '<td class="m93_t_col50" id="preis_3">xy</td>'
union all select '<td class="m95_t_col5" style="fuzzy" id="preis_5">xz</td>'
union all select '<td id="preis_8" class="m29_t_col5">no fix req</td>'
)
SELECT
D.html
, dbo.ClassIdSwap(D.html) AS modified
FROM
SAMPLE_DATA D
