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Re: != should give error? - Mailing list pgsql-hackers

From Craig Ringer
Subject Re: != should give error?
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Msg-id CAMsr+YF7ocp4ZunCjB_GSFc-=uqyAXoCgWxw-j7hgHRt66Tm0g@mail.gmail.com
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In response to != should give error?  (Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>)
Responses Re: != should give error?
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On 21 December 2017 at 14:43, Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com> wrote:
Hi,

with below query I am getting unexpected output. here !<space>= is behaving as =
is this expected behaviour?

postgres=# create table tbl (col_a int, col_b int);
CREATE TABLE
postgres=# insert into tbl values (1,2);
INSERT 0 1
postgres=# insert into tbl values (2,1);
INSERT 0 1
postgres=# select * from tbl where col_a ! = 1;
 col_a | col_b
-------+-------
     1 |     2
(1 row)


One-factorial is one, so it's correct.

test=> SELECT 1!, 2!, 3!;
 ?column? | ?column? | ?column? 
----------+----------+----------
        1 |        2 |        6
(1 row)

test=> SELECT (1 !) = 1;
 ?column? 
----------
 t
(1 row)

test=> \do+ !
                                      List of operators
   Schema   | Name | Left arg type | Right arg type | Result type |  Function   | Description 
------------+------+---------------+----------------+-------------+-------------+-------------
 pg_catalog | !    | bigint        |                | numeric     | numeric_fac | factorial
(1 row)




--
 Craig Ringer                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

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