Mixing
In PostGreSQL should the back references of a regexp_replace work in a CASE statement?
Example (the ELSE always gets chosen):
SELECT regexp_replace('ABCDEFG','(C)(D)', CASE WHEN '1' = 'C' THEN '+21+' ELSE '-12-' END);
**returns =>** AB-CD-EFG
SELECT regexp_replace('ABCDEFG','(C)(D)', CASE '1' WHEN 'C' THEN '+21+' ELSE '-12-' END);
**returns =>** AB-CD-EFG
Is there a way to make this work?
regex postgresql switch-statement
asked Nov 19 '18 at 21:42
PetePete
34036
add a comment |
Example (the ELSE always gets chosen):
SELECT regexp_replace('ABCDEFG','(C)(D)', CASE WHEN '1' = 'C' THEN '+21+' ELSE '-12-' END);
**returns =>** AB-CD-EFG
SELECT regexp_replace('ABCDEFG','(C)(D)', CASE '1' WHEN 'C' THEN '+21+' ELSE '-12-' END);
**returns =>** AB-CD-EFG
Is there a way to make this work?
regex postgresql switch-statement
asked Nov 19 '18 at 21:42
PetePete
34036
It seems the '1' in the WHEN is a literal and not a back-reference but the result in the THEN can contain back-references. I am using PostGres 9.4.
– Pete
Nov 19 '18 at 22:27
add a comment |
Example (the ELSE always gets chosen):
SELECT regexp_replace('ABCDEFG','(C)(D)', CASE WHEN '1' = 'C' THEN '+21+' ELSE '-12-' END);
**returns =>** AB-CD-EFG
SELECT regexp_replace('ABCDEFG','(C)(D)', CASE '1' WHEN 'C' THEN '+21+' ELSE '-12-' END);
**returns =>** AB-CD-EFG
Is there a way to make this work?
regex postgresql switch-statement
asked Nov 19 '18 at 21:42
PetePete
34036
Example (the ELSE always gets chosen):
SELECT regexp_replace('ABCDEFG','(C)(D)', CASE WHEN '1' = 'C' THEN '+21+' ELSE '-12-' END);
**returns =>** AB-CD-EFG
SELECT regexp_replace('ABCDEFG','(C)(D)', CASE '1' WHEN 'C' THEN '+21+' ELSE '-12-' END);
**returns =>** AB-CD-EFG
Is there a way to make this work?
regex postgresql switch-statement
regex postgresql switch-statement
asked Nov 19 '18 at 21:42
PetePete
34036
asked Nov 19 '18 at 21:42
PetePete
34036
asked Nov 19 '18 at 21:42
PetePete
34036
asked Nov 19 '18 at 21:42
PetePete
34036
asked Nov 19 '18 at 21:42
PetePete
34036
34036
It seems the '1' in the WHEN is a literal and not a back-reference but the result in the THEN can contain back-references. I am using PostGres 9.4.
– Pete
Nov 19 '18 at 22:27
add a comment |
It seems the '1' in the WHEN is a literal and not a back-reference but the result in the THEN can contain back-references. I am using PostGres 9.4.
– Pete
Nov 19 '18 at 22:27
It seems the '1' in the WHEN is a literal and not a back-reference but the result in the THEN can contain back-references. I am using PostGres 9.4.
– Pete
Nov 19 '18 at 22:27
It seems the '1' in the WHEN is a literal and not a back-reference but the result in the THEN can contain back-references. I am using PostGres 9.4.
– Pete
Nov 19 '18 at 22:27
add a comment |
1 Answer
1
active
oldest
votes
No it shouldn't.
I would use regexp_match with groups for the stuff before C and after D as well, and then construct the result from the matched parts using CASE and concatenation.
answered Nov 19 '18 at 22:29
Alexey BashtanovAlexey Bashtanov
38435
add a comment |
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1 Answer
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1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
No it shouldn't.
I would use regexp_match with groups for the stuff before C and after D as well, and then construct the result from the matched parts using CASE and concatenation.
answered Nov 19 '18 at 22:29
Alexey BashtanovAlexey Bashtanov
38435
add a comment |
No it shouldn't.
I would use regexp_match with groups for the stuff before C and after D as well, and then construct the result from the matched parts using CASE and concatenation.
answered Nov 19 '18 at 22:29
Alexey BashtanovAlexey Bashtanov
38435
add a comment |
No it shouldn't.
I would use regexp_match with groups for the stuff before C and after D as well, and then construct the result from the matched parts using CASE and concatenation.
answered Nov 19 '18 at 22:29
Alexey BashtanovAlexey Bashtanov
38435
No it shouldn't.
I would use regexp_match with groups for the stuff before C and after D as well, and then construct the result from the matched parts using CASE and concatenation.
answered Nov 19 '18 at 22:29
Alexey BashtanovAlexey Bashtanov
38435
answered Nov 19 '18 at 22:29
Alexey BashtanovAlexey Bashtanov
38435
answered Nov 19 '18 at 22:29
Alexey BashtanovAlexey Bashtanov
38435
answered Nov 19 '18 at 22:29
Alexey BashtanovAlexey Bashtanov
38435
38435
add a comment |
add a comment |
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It seems the '1' in the WHEN is a literal and not a back-reference but the result in the THEN can contain back-references. I am using PostGres 9.4.
– Pete
Nov 19 '18 at 22:27