postgresql Remove trailing zeroes

问题

I have a query which is proving to be cumbersome for me. I want to remove the trailing zeroes from the result.

Remove trailing zeros from decimal in SQL Server

Remove trailing zeroes using sql

 select concat(100 * round(cast(count(ft.*) filter (where "Realtor_Sale" = 'Yes') 
as numeric(12,5)) / 
cast(count(ft.*) as numeric(12,5)),3),'%') as "Realtor Sales"

Result I am getting is:

84.800% --------------> I want 84.8%.

I tried doing this as well:

select concat(100 * round(cast(cast(count(ft.*) filter (where "Realtor_Sale" = 'Yes') 
as decimal(18,5)) as float) / 
cast(cast(count(ft.*) as decimal(18,5)) as float),3), '%') as "Realtor Sales"

Error:

ERROR:  function round(double precision, integer) does not exist
select round(cast(cast(count(ft.*) filter (where "Realtor_Sa...

How do I get the result to round of to 84.8%?

回答1:

No need for the many casts, just use to_char() on the result:

select to_char((100 * count(ft.*) filter (where "Realtor_Sale" = 'Yes'))::decimal 
                / count(ft.*), 'FM99.0%') as "Realtor Sales"

回答2:

With PostgreSQL 13 it is matter of calling trim_scale function:

trim_scale ( numeric ) → numeric

Reduces the value's scale (number of fractional decimal digits) by removing trailing zeroes

trim_scale(8.4100) → 8.41

select trim_scale(100.0 * count(ft.*) filter (where "Realtor_Sale" = 'Yes')/ 
                  count(ft.*) ) ||'%'as "Realtor Sales"

db<>fiddle demo

来源：https://stackoverflow.com/questions/42721281/postgresql-remove-trailing-zeroes

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sql

postgresql