Update Numeric field without Decimal point and Zeros - postgresql

Question

I am trying to update a numeric field. But the field can not have zeros after decimal point. But the table that I am trying to pull values contain data as 87.00,90.00,100.00 etc.. How do I update without decimal point and zeros?
Example :percentage is a numeric field.
Update value available 100.00,90.00 etc.
update table1
set percent =(tmpercent as integer)
from table2
where table2.custid=table1.custoid;
;
gives error.
Table1:
CustID Percent(numeric)
1 90
2 80
Table2:
CustomID tmpPercent(varchar)
1 87.00
2 90.00

Answer 1

i often use typecasting ::FLOAT::NUMERIC to get rid of extra fraction zeros of numerics
or you can use TRUNC() function to force fraction truncation
try
update table1
set percent = tmpercent::FLOAT::NUMERIC
from table2
where table2.custid=table1.custoid;
or
update table1
set percent = TRUNC(tmpercent::NUMERIC)
from table2
where table2.custid=table1.custoid;

Answer 2

It is going to depend on how the numeric field is specified in the table. From here:
https://www.postgresql.org/docs/current/datatype-numeric.html
We use the following terms below: The precision of a numeric is the total count of significant digits in the whole number, that is, the number of digits to both sides of the decimal point. The scale of a numeric is the count of decimal digits in the fractional part, to the right of the decimal point. So the number 23.5141 has a precision of 6 and a scale of 4. Integers can be considered to have a scale of zero.
NUMERIC(precision, scale)
So if your field has a scale > 0 then you will see 0 to the right of the decimal point, unless you set scale to 0. As example:
create table numeric_test (num_fld numeric(5,2), num_fld_0 numeric(5,0));
insert into numeric_test (num_fld, num_fld_0) values ('90.0', '90.0');
select * from numeric_test ;
num_fld | num_fld_0
---------+-----------
90.00 | 90
insert into numeric_test (num_fld, num_fld_0) values ('90.5', '90.5');
select * from numeric_test ;
num_fld | num_fld_0
---------+-----------
90.00 | 90
90.50 | 91
insert into numeric_test (num_fld, num_fld_0) values ('90.0'::float, '90.0'::float);
select * from numeric_test ;
num_fld | num_fld_0
---------+-----------
90.00 | 90
90.50 | 91
90.00 | 90
Using scale 0 means you have basically created an integer field. If you have a scale > 0 then you are going to get decimals in the field.