Re: How do I remove selected words from text field?
От | Frank Bax |
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Тема | Re: How do I remove selected words from text field? |
Дата | |
Msg-id | BLU0-SMTP7888ACA3DFCEDA21C88B69ACCD0@phx.gbl обсуждение исходный текст |
Ответ на | Re: How do I remove selected words from text field? (Frank Bax <fbax@sympatico.ca>) |
Ответы |
Re: How do I remove selected words from text field?
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Список | pgsql-sql |
Create some tables; then add some data: create table t1 (i int, v varchar); insert into t1 values(1,'A B C D'); insert into t1 values(2,'B D E F'); insert into t1 values(3,'G H I J'); insert into t1 values(4,'E'); create table t2 (q varchar, z varchar); insert into t2 values('A','vowel'); insert into t2 values('B','consonant'); insert into t2 values('E','vowel'); insert into t2 values('K','consonant'); I am trying to write a function which will: * split the argument into "words" (separated by blanks); * remove words that meet a certain condition in another table (in this example 'vowel'); * reassemble "words" into a string; * return the result This query does that job (Thanks Osvaldo): SELECT i, array_to_string(array_agg(word), ' ') "new-v" FROM (SELECT * FROM (SELECT i, regexp_split_to_table(v, E'\\s+') AS word FROM t1) bar LEFT OUTER JOIN t2 ON (bar.word=t2.q) WHERE z IS DISTINCT FROM 'vowel') foo GROUP BY i; i | new-v ---+--------- 1 | B C D 3 | G H I J 2 | B D F (3 rows) When I try to create a function to do the same thing; it only works for (4,'E') and not the other tuples. CREATE OR REPLACE FUNCTION notvowel(text) RETURNS text AS $$ SELECT array_to_string(array_agg(word),' ') FROM (SELECT *FROM (SELECT regexp_split_to_table($1, E'\s+') AS word) bar LEFT OUTER JOIN t2 ON (bar.word=t2.q) WHERE z IS DISTINCTFROM 'vowel') foo GROUP BY word $$ LANGUAGE SQL; select *,notvowel(v::text) from t1; i | v | notvowel ---+---------+---------- 1 | A B C D | A B C D 2 | B D E F | B D E F 3 | G H I J | G H I J 4 | E | (4 rows) I wonder if it has something to do with pattern passed to regexp_split_to_table() since inside the function, E'\\s+' results in: i | v | notvowel ---+---------+---------- 1 | A B C D | C 2 | B D E F | B 3 | G H I J | G 4 | E | (4 rows)
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