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Bring SIMILAR TO and SUBSTRING into some semblance of conformance with

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the SQL99 standard.  (I'm not sure that the character-class features are
quite right, but that can be fixed later.)  Document SQL99 and POSIX
regexps as being different features; provide variants of SUBSTRING for
each.
This commit is contained in:
Tom Lane
2002-09-22 17:27:25 +00:00
parent ac355d558e
commit 9946b83ded
7 changed files with 683 additions and 381 deletions
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15
src/test/regress/sql/strings.sql
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@@ -62,19 +62,24 @@ SELECT SUBSTRING('1234567890' FROM 3) = '34567890' AS "34567890";
SELECT SUBSTRING('1234567890' FROM 4 FOR 3) = '456' AS "456";
-- T581 regular expression substring
SELECT SUBSTRING('abcdefg' FROM '(b|f).*(d)' FOR '#') AS "bcd";
-- T581 regular expression substring (with SQL99's bizarre regexp syntax)
SELECT SUBSTRING('abcdefg' FROM 'a#"(b_d)#"%' FOR '#') AS "bcd";
-- No match should return NULL
SELECT SUBSTRING('abcdefg' FROM '(1|2|3)' FOR '#') IS NULL AS "True";
SELECT SUBSTRING('abcdefg' FROM '#"(b_d)#"%' FOR '#') IS NULL AS "True";
-- Null inputs should return NULL
SELECT SUBSTRING('abcdefg' FROM '(b|c)' FOR NULL) IS NULL AS "True";
SELECT SUBSTRING(NULL FROM '(b|c)' FOR '#') IS NULL AS "True";
SELECT SUBSTRING('abcdefg' FROM NULL FOR '#') IS NULL AS "True";
-- PostgreSQL extention to allow omitting the escape character
SELECT SUBSTRING('abcdefg' FROM '(c|d).e') AS "cde";
-- PostgreSQL extension to allow omitting the escape character;
-- here the regexp is taken as Posix syntax
SELECT SUBSTRING('abcdefg' FROM 'c.e') AS "cde";
-- With a parenthesized subexpression, return only what matches the subexpr
SELECT SUBSTRING('abcdefg' FROM 'b(.*)f') AS "cde";
-- E021-11 position expression
SELECT POSITION('4' IN '1234567890') = '4' AS "4";