On Thu, Dec 28, 2023 at 12:13 AM jian he <jian.universal...@gmail.com> wrote:
>
> hi.
> https://git.postgresql.org/cgit/postgresql.git/tree/src/test/regress/expected/strings.out#n928
>
> SELECT regexp_substr('abcabcabc', 'a.c');
> SELECT regexp_substr('abcabcabc', 'a.c', 2);
> SELECT regexp_substr('abcabcabc', 'a.c', 1, 3);
> SELECT regexp_substr('abcabcabc', 'a.c', 1, 4) IS NULL AS t;
> SELECT regexp_substr('abcabcabc', 'A.C', 1, 2, 'i');
>
> they all return 'abc', there are 3 'abc ' in string 'abcabcabc'
> except IS NULL query.
> maybe we can change regexp_substr first argument from "abcabcabc" to
> "abcaXcaYc".
> so the result would be more easier to understand.
anyway here is the minor patch to change string from "abcabcabc" to
"abcaXcaYc".
From ffe63d9607824e6aa89d590761fcb05219b799d8 Mon Sep 17 00:00:00 2001
From: pgaddict <jian.universal...@gmail.com>
Date: Thu, 28 Dec 2023 14:11:31 +0800
Subject: [PATCH v1 1/1] make regexp_substr result more easier to understand.
regexp_substr using "abcabcabc" is not good for test,
since in many cases, it will return "abc".
there are 3 "abc" in "abcabcabc", change the test string to something else
make the results more clear.
---
src/test/regress/expected/strings.out | 14 +++++++-------
src/test/regress/sql/strings.sql | 8 ++++----
2 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/src/test/regress/expected/strings.out b/src/test/regress/expected/strings.out
index b7500d9c..7098934a 100644
--- a/src/test/regress/expected/strings.out
+++ b/src/test/regress/expected/strings.out
@@ -925,22 +925,22 @@ SELECT regexp_substr('abcdefghi', 'd.q') IS NULL AS t;
t
(1 row)
-SELECT regexp_substr('abcabcabc', 'a.c');
+SELECT regexp_substr('abcaXcaYc', 'a.c');
regexp_substr
---------------
abc
(1 row)
-SELECT regexp_substr('abcabcabc', 'a.c', 2);
+SELECT regexp_substr('abcaXcaYc', 'a.c', 2);
regexp_substr
---------------
- abc
+ aXc
(1 row)
-SELECT regexp_substr('abcabcabc', 'a.c', 1, 3);
+SELECT regexp_substr('abcaXcaYc', 'a.c', 1, 3);
regexp_substr
---------------
- abc
+ aYc
(1 row)
SELECT regexp_substr('abcabcabc', 'a.c', 1, 4) IS NULL AS t;
@@ -949,10 +949,10 @@ SELECT regexp_substr('abcabcabc', 'a.c', 1, 4) IS NULL AS t;
t
(1 row)
-SELECT regexp_substr('abcabcabc', 'A.C', 1, 2, 'i');
+SELECT regexp_substr('abcaXcaYc', 'A.C', 1, 2, 'i');
regexp_substr
---------------
- abc
+ aXc
(1 row)
SELECT regexp_substr('1234567890', '(123)(4(56)(78))', 1, 1, 'i', 0);
diff --git a/src/test/regress/sql/strings.sql b/src/test/regress/sql/strings.sql
index 39596789..4ed86516 100644
--- a/src/test/regress/sql/strings.sql
+++ b/src/test/regress/sql/strings.sql
@@ -274,11 +274,11 @@ SELECT regexp_instr('abcabcabc', 'a.c', 1, 1, 0, '', -1);
-- regexp_substr tests
SELECT regexp_substr('abcdefghi', 'd.f');
SELECT regexp_substr('abcdefghi', 'd.q') IS NULL AS t;
-SELECT regexp_substr('abcabcabc', 'a.c');
-SELECT regexp_substr('abcabcabc', 'a.c', 2);
-SELECT regexp_substr('abcabcabc', 'a.c', 1, 3);
+SELECT regexp_substr('abcaXcaYc', 'a.c');
+SELECT regexp_substr('abcaXcaYc', 'a.c', 2);
+SELECT regexp_substr('abcaXcaYc', 'a.c', 1, 3);
SELECT regexp_substr('abcabcabc', 'a.c', 1, 4) IS NULL AS t;
-SELECT regexp_substr('abcabcabc', 'A.C', 1, 2, 'i');
+SELECT regexp_substr('abcaXcaYc', 'A.C', 1, 2, 'i');
SELECT regexp_substr('1234567890', '(123)(4(56)(78))', 1, 1, 'i', 0);
SELECT regexp_substr('1234567890', '(123)(4(56)(78))', 1, 1, 'i', 1);
SELECT regexp_substr('1234567890', '(123)(4(56)(78))', 1, 1, 'i', 2);
--
2.34.1
