You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@calcite.apache.org by 18390992640 <m1...@163.com> on 2018/06/10 00:38:45 UTC
calcite support bit operation
Hello EveryOne ！
I have seed calcite SqlKind.java source code, find that it hasn't bit operation. so I want to ask why calcite don't support bit operation. for example, follow Query statement, it not support.
select col_a, col_b from table_1 where (col_a & col_b) > 10.
if I want to extend calcite to supoort bit operation, how difficulty may be？
who knwo this, please give me a help. thanks very mush!
回复： calcite support bit operation
Posted by 张建 <15...@qq.com>.
In MySQL:
the supported builtin bit functions and operators are: BIT_COUNT, &, |, ^, ~, << and >>
the supported builtin bit aggregations are: BIT_AND, BIT_OR and BIT_XOR
For example:
MySQL(localhost:3306) > select 1 ^ 2; +-------+ | 1 ^ 2 | +-------+ | 3 | +-------+ 1 row in set (0.01 sec) MySQL(localhost:3306) > select bit_or(a), b from t group by b; +-----------+------+ | bit_or(a) | b | +-----------+------+ | 3 | 1 | | 3 | 2 | +-----------+------+ 2 rows in set (0.00 sec)
See the following links for more details:
https://dev.mysql.com/doc/refman/5.7/en/bit-functions.html
https://dev.mysql.com/doc/refman/5.7/en/group-by-functions.html
------------------ 原始邮件 ------------------
发件人: "Julian Hyde"<jh...@apache.org>;
发送时间: 2018年6月10日(星期天) 中午12:31
收件人: "dev"<de...@calcite.apache.org>;
主题: Re: calcite support bit operation
PS Can you see what support for bit operations is in other databases? It would be quite straightforward to add new functions, less easy to add “&” or “|” or “~”.
> On Jun 9, 2018, at 6:47 PM, Julian Hyde <jh...@apache.org> wrote:
>
> BIt operations are not standard SQL.
>
> Are there any databases that support them? (I’m guessing MySQL, which at one point seemed to have a mission to convert SQL into C, even down to using int instead of boolean.)
>
> We could perhaps add support for bit operations, but I would not like to add an ‘&’ operator. It would be too disruptive to the parser. Maybe it could go into Babel.
>
> Julian
>
>> On Jun 9, 2018, at 5:38 PM, 18390992640 <m1...@163.com> wrote:
>>
>> Hello EveryOne ！
>> I have seed calcite SqlKind.java source code, find that it hasn't bit operation. so I want to ask why calcite don't support bit operation. for example, follow Query statement, it not support.
>> select col_a, col_b from table_1 where (col_a & col_b) > 10.
>> if I want to extend calcite to supoort bit operation, how difficulty may be？
>> who knwo this, please give me a help. thanks very mush!
>
Re: calcite support bit operation
Posted by Julian Hyde <jh...@apache.org>.
PS Can you see what support for bit operations is in other databases? It would be quite straightforward to add new functions, less easy to add “&” or “|” or “~”.
> On Jun 9, 2018, at 6:47 PM, Julian Hyde <jh...@apache.org> wrote:
>
> BIt operations are not standard SQL.
>
> Are there any databases that support them? (I’m guessing MySQL, which at one point seemed to have a mission to convert SQL into C, even down to using int instead of boolean.)
>
> We could perhaps add support for bit operations, but I would not like to add an ‘&’ operator. It would be too disruptive to the parser. Maybe it could go into Babel.
>
> Julian
>
>> On Jun 9, 2018, at 5:38 PM, 18390992640 <m1...@163.com> wrote:
>>
>> Hello EveryOne ！
>> I have seed calcite SqlKind.java source code, find that it hasn't bit operation. so I want to ask why calcite don't support bit operation. for example, follow Query statement, it not support.
>> select col_a, col_b from table_1 where (col_a & col_b) > 10.
>> if I want to extend calcite to supoort bit operation, how difficulty may be？
>> who knwo this, please give me a help. thanks very mush!
>
Re: calcite support bit operation
Posted by Julian Hyde <jh...@apache.org>.
BIt operations are not standard SQL.
Are there any databases that support them? (I’m guessing MySQL, which at one point seemed to have a mission to convert SQL into C, even down to using int instead of boolean.)
We could perhaps add support for bit operations, but I would not like to add an ‘&’ operator. It would be too disruptive to the parser. Maybe it could go into Babel.
Julian
> On Jun 9, 2018, at 5:38 PM, 18390992640 <m1...@163.com> wrote:
>
> Hello EveryOne ！
> I have seed calcite SqlKind.java source code, find that it hasn't bit operation. so I want to ask why calcite don't support bit operation. for example, follow Query statement, it not support.
> select col_a, col_b from table_1 where (col_a & col_b) > 10.
> if I want to extend calcite to supoort bit operation, how difficulty may be？
> who knwo this, please give me a help. thanks very mush!