Postgresql:生成序列 [英] Postgresql:Generate Sequence

问题描述

下面的查询生成一行 DNA 序列

The query below generates a line of DNA sequence

prepare dna_length(int) as
with t1 as (select chr(65) as s union select chr(67) union select chr(71) union select chr(84) ),

 t2 as ( select s, row_number() over() as rn from t1),

 t3 as ( select generate_series(1,$1) as i,round(random() * 4 + 0.5) as rn ),

 t4 as ( select t2.s from t2 join t3 on (t2.rn=t3.rn))

select array_to_string(array(select s from t4),'') as dna ;

execute dna_length(20);

结果 - dnaCCCGGTTCTCCCCATGCAGG

Result - dna CCCGGTTCTCCCCATGCAGG

我想生成 10 个随机 DNA 序列

I will like to generate 10 random DNA SEQUENCES

推荐答案

类似的事情?

select x, string_agg((array['A', 'C', 'G', 'T'])[1 + floor(random() * 4)], '')
from generate_series(1, 20, 1) gsn(n) cross join
     generate_series(1, 10, 1) gsx(x)
group by x

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