Thanks Pavel for fast response.
On Sun, Dec 13, 2020 at 9:51 AM Pavel Stehule <pavel.steh...@gmail.com>
wrote:
> Hi
>
> ne 13. 12. 2020 v 18:42 odesílatel Zhihong Yu <z...@yugabyte.com> napsal:
>
>> Hi,
>> I was experimenting with the following query.
>>
>> create table sint1(k int primary key, arr smallint[]);
>> create index s1 on sint1(arr);
>> insert into sint1 select s, array[s*s, s] FROM generate_series(1, 10) AS
>> s;
>> select * from sint1 where arr @> array[4];
>> ERROR: operator does not exist: smallint[] @> integer[]
>> LINE 1: select * from sint1 where arr @> array[4];
>> ^
>> HINT: No operator matches the given name and argument types. You might
>> need to add explicit type casts.
>> -------
>>
>> I wonder if someone can enlighten me on the correct way to perform the
>> type cast.
>>
>
>
> postgres=# select * from sint1 where arr @> array[4::smallint];
> ┌───┬────────┐
> │ k │ arr │
> ╞═══╪════════╡
> │ 2 │ {4,2} │
> │ 4 │ {16,4} │
> └───┴────────┘
> (2 rows)
>
> postgres=# select * from sint1 where arr @> array[4]::smallint[];
> ┌───┬────────┐
> │ k │ arr │
> ╞═══╪════════╡
> │ 2 │ {4,2} │
> │ 4 │ {16,4} │
> └───┴────────┘
> (2 rows)
>
> postgres=#
>
>
>>
>> Thanks
>>
>
