gbase8s数据库获取随机数方法

在早期的数据库版本中,没有获取随机数的函数,为此,提供如下几种方式,仅供测试参考,具体使用请联系gbase8s官方技术支持

--简单的线性同余生成器(LCG)的变种
drop function if exists ff1;
create function ff1() returning int

define a int;
let a= DBINFO('utc_current');  
let a= (IFX_BIT_RIGHTSHIFT(a,5)) + (IFX_BIT_LEFTSHIFT(a,7));
let a= BITAND(a,2147483647);   --& 0x7FFFFFFF; // 取低31位作为结果,避免符号位影响
let a=mod(a,101); --将结果映射到[0,100]区间
return a;
end function;

--XORSHIFT算法
drop function if exists ff2;
create function ff2() returning int

define a int;
let a=DBINFO('utc_current');
let a= BITXOR(a,IFX_BIT_LEFTSHIFT(a,13));
let a= BITXOR(a,IFX_BIT_RIGHTSHIFT(a,7));
let a= BITXOR(a,IFX_BIT_LEFTSHIFT(a,17));
let a= BITAND(a,2147483647);
let a=mod(a,101);

return a;
end function;

--简单的位移运算

drop function if exists ff3;
create function ff3() returning int
define a int;
let a=DBINFO('utc_current');
let a=BITXOR(BITXOR(IFX_BIT_LEFTSHIFT(a,13),IFX_BIT_RIGHTSHIFT(a,9)),IFX_BIT_LEFTSHIFT(a,5));
let a= BITAND(a,2147483647);
let a=mod(a,101);
return a;
end function;

%E5%8F%AA%E8%A6%81%E5%86%99%E8%BF%87%E4%BB%A3%E7%A0%81%E7%9A%84%E9%83%BD%E7%9F%A5%E9%81%93%EF%BC%8C%E5%BD%93%E4%BD%A0%E7%9A%84%E4%BB%A3%E7%A0%81%E8%BF%9B%E8%A1%8C%E7%BC%96%E8%AF%91%E9%93%BE%E6%8E%A5%E5%90%8E%E4%BE%BF%E4%BC%9A%E7%94%9F%E6%88%90%E4%B8%80%E4%B8%AA%E5%8F%AF%E6%89%A7%E8%A1%8C%E7%A8%8B%E5%BA%8F%EF%BC%8C%E8%BF%99%E4%B8%AA%E5%8F%AF%E6%89%A7%E8%A1%8C%E7%A8%8B%E5%BA%8F%E6%9C%AC%E8%B4%A8%E4%B8%8A%E6%98%AF%E4%B8%80%E4%B8%AA%E6%96%87%E4%BB%B6%EF%BC%8C%E6%98%AF%E6%94%BE%E5%9C%A8%E7%A3%81%E7%9B%98%E4%B8%8A%E7%9A%84%E3%80%82%E5%BD%93%E6%88%91%E4%BB%AC%E5%8F%8C%E5%87%BB%E8%BF%99%E4%B8%AA%E5%8F%AF%E6%89%A7%E8%A1%8C%E7%A8%8B%E5%BA%8F%E5%B0%86%E5%85%B6%E8%BF%90%E8%A1%8C%E8%B5%B7%E6%9D%A5%E6%97%B6%EF%BC%8C%E6%9C%AC%E8%B4%A8%E4%B8%8A%E6%98%AF%E5%B0%86%E8%BF%99%E4%B8%AA%E7%A8%8B%E5%BA%8F%E5%8A%A0%E8%BD%BD%E5%88%B0%E5%86%85%E5%AD%98%E5%BD%93%E4%B8%AD%E4%BA%86%EF%BC%8C%E5%9B%A0%E4%B8%BA%E5%8F%AA%E6%9C%89%E5%8A%A0%E8%BD%BD%E5%88%B0%E5%86%85%E5%AD%98%E5%90%8E%EF%BC%8CCPU%E6%89%8D%E8%83%BD%E5%AF%B9%E5%85%B6%E8%BF%9B%E8%A1%8C%E9%80%90%E8%A1%8C%E7%9A%84%E8%AF%AD%E5%8F%A5%E6%89%A7%E8%A1%8C%EF%BC%8C%E8%80%8C%E4%B8%80%E6%97%A6%E5%B0%86%E8%BF%99%E4%B8%AA%E7%A8%8B%E5%BA%8F%E5%8A%A0%E8%BD%BD%E5%88%B0%E5%86%85%E5%AD%98%E5%90%8E%EF%BC%8C%E6%88%91%E4%BB%AC%E5%B0%B1%E4%B8%8D%E5%BA%94%E8%AF%A5%E5%B0%86%E8%BF%99%E4%B8%AA%E7%A8%8B%E5%BA%8F%E5%86%8D%E5%8F%AB%E5%81%9A%E7%A8%8B%E5%BA%8F%E4%BA%86%EF%BC%8C%E4%B8%A5%E6%A0%BC%E6%84%8F%E4%B9%89%E4%B8%8A%E5%B0%86%E5%BA%94%E8%AF%A5%E5%B0%86%E5%85%B6%E7%A7%B0%E4%B9%8B%E4%B8%BA%E8%BF%9B%E7%A8%8B%E3%80%82
最新发布
05-20
%E5%A6%82%E4%B8%8A%E5%9B%BE%EF%BC%88%E5%8F%82%E8%80%83%E5%88%AB%E5%A4%84%E7%9A%84%EF%BC%89%E6%88%91%E4%BB%AC%E8%BF%9B%E8%A1%8C%E4%B8%80%E4%BA%9B%E5%88%86%E6%9E%90%EF%BC%9B%5Cn%5Cnrst_async_n+%E7%94%9F%E6%95%88+%E5%8D%B3%28rst_async_n%3D%3D1+-%3E+rst_async_n%3D%3D0%29%5Cn%E6%AD%A4%E6%97%B61%E6%A1%86%E5%86%85%E7%9A%84%E5%AF%84%E5%AD%98%E5%99%A8%E6%98%AF%E9%A9%AC%E4%B8%8A%E6%9B%B4%E6%96%B0%E7%9A%84%EF%BC%8C%E6%89%80%E4%BB%A5%E8%BE%93%E5%87%BA%E7%9A%84rst_sync_n%E4%B9%9F%E6%98%AF%E9%A9%AC%E4%B8%8A%E5%8F%AF%E4%BB%A5%E4%BD%93%E7%8E%B0%E5%87%BA%E6%9D%A5%E7%9A%84%EF%BC%8C%E5%AE%9E%E7%8E%B0%E5%AF%B92%E6%A1%86%E5%86%85%E7%9A%84%E7%94%B5%E8%B7%AF%E8%BF%9B%E8%A1%8C%E5%BC%82%E6%AD%A5%E5%A4%8D%E4%BD%8D%EF%BC%9B%5Cnrst_async_n+%E6%97%A0%E6%95%88+%E5%8D%B3%EF%BC%88rst_async_n%3D%3D0+-%3E+rst_async_n%3D%3D1%EF%BC%89%5Cn%E6%AD%A4%E6%97%B6%E7%94%B1%E4%BA%8E%E7%94%B5%E8%B7%AF%E8%AE%BE%E8%AE%A1%E6%97%B6%EF%BC%8C%E5%9B%BE%E4%B8%8A%E5%AF%84%E5%AD%98%E5%99%A8%E5%8F%AA%E5%AF%B9%E5%A4%8D%E4%BD%8D%E4%BF%A1%E5%8F%B7%E7%9A%84%E4%B8%8B%E9%99%8D%E6%B2%BF%E6%95%8F%E6%84%9F%EF%BC%8C%E6%89%80%E4%BB%A5%E5%BD%93%E5%A4%B1%E6%95%88%E6%A8%A1%E5%BC%8F%E4%B8%8B%EF%BC%8C%E5%B9%B6%E4%B8%8D%E4%BC%9A%E9%A9%AC%E4%B8%8A%E6%9B%B4%E6%96%B0%EF%BC%8C%E6%89%80%E4%BB%A5%E5%B0%B1%E7%AE%97%E4%BD%A0%E7%9A%84%E5%A4%8D%E4%BD%8D%E4%BF%A1%E5%8F%B7%E5%9C%A81%E6%A1%86%E4%B8%AD%E7%AC%AC%E4%B8%80%E4%B8%AA%E5%AF%84%E5%AD%98%E5%99%A8%E7%9A%84%E6%97%B6%E9%92%9F%E6%B2%BF%E8%BF%9B%E8%A1%8C%E5%8F%98%E5%8C%96%EF%BC%8C%E4%BD%86%E6%98%AF%E7%94%B1%E4%BA%8E%E4%B8%AD%E9%97%B4%E5%8A%A0%E4%BA%86%E4%B8%80%E4%B8%AA%E5%AF%84%E5%AD%98%E5%99%A8%E4%B8%8D%E4%BC%9A%E7%AB%8B%E9%A9%AC%E4%BC%A0%E5%88%B0%E6%A1%862%E4%B8%AD%E5%8E%BB%EF%BC%88%E8%BF%99%E4%B8%AA%E5%AF%84%E5%AD%98%E5%99%A8%E5%B0%B1%E6%98%AF%E6%8B%BF%E6%9D%A5%E5%90%8C%E6%AD%A5%E7%9A%84%EF%BC%89%EF%BC%9B%E5%AE%9E%E7%8E%B0%E4%BA%86%E5%90%8C%E6%AD%A5%E9%87%8A%E6%94%BE%EF%BC%9B
05-18
评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值