How to insert data pass by parameter

Hi support
I have problem about insertion into postgres db and details
like below;
1. I use IBM DataStage as client connect to Postgrest db 8.2.4 via
psqlOdbc 8.0.4
2. I can read data from table but I cannot insert data in to target table
on Postgrest DB and I 've got error message like this

"SQL statement:INSERT INTO a(emp_id) VALUES (?)
SQLSTATE=00000, DBMS.CODE=-1
[DataStage][SQL Client][ODBC][unixODBC]Error while executing the query
(non-fatal);
ERROR: syntax error at end of input at character 47 "

Table name : a
Col Name :emp_id char(10)
Sql Statement : insert into a (emp_id) values (?);
I use (?) for passing data by parameter.

Please give me a suggestion for using insert data by pass parameter

Thanks