From: PG Bug reporting form <noreply@postgresql.org>
To: pgsql-bugs@lists.postgresql.org
Cc: ammmkilo@163.com
Subject: BUG #18560: Inconsistent Behavior of PostgreSQL 'LIKE' Operator
Date: Wed, 31 Jul 2024 04:47:23 +0000
Message-ID: <18560-c6c21c3b8d5c3f9b@postgresql.org> (raw)
The following bug has been logged on the website:
Bug reference: 18560
Logged by: Hang ammmkilo
Email address: ammmkilo@163.com
PostgreSQL version: 16.3
Operating system: ubuntu 20.04
Description:
```create table
DROP TABLE IF EXISTS t0;
CREATE TABLE t0(c0 INT NOT NULL, c1 CHAR(1) UNIQUE);
INSERT INTO t0 VALUES (0, '1');
INSERT INTO t0 VALUES (0, '');
```
---sql1
select ('' like ''),('1' like '1');
?column? | ?column?
----------+----------
t | t
(1 row)
---sql2
select c1,(c1 like c1) from t0;
c1 | ?column?
----+----------
1 | t
| f
(2 rows)
In sql1, the result of the (" like ") query returns true. In sql2 (c1 like
c1) the return value is false when c1 is ".
I think this is contradictory and there may be some bug between the 'like'
and the query column.
---select version():
version
---------------------------------------------------------------------------------------------------------------------
PostgreSQL 16.3 (Debian 16.3-1.pgdg120+1) on x86_64-pc-linux-gnu, compiled
by gcc (Debian 12.2.0-14) 12.2.0, 64-bit
(1 row)
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To: pgsql-bugs@postgresql.org
Cc: noreply@postgresql.org, pgsql-bugs@lists.postgresql.org, ammmkilo@163.com
Subject: Re: BUG #18560: Inconsistent Behavior of PostgreSQL 'LIKE' Operator
In-Reply-To: <18560-c6c21c3b8d5c3f9b@postgresql.org>
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