i want import that backup sql file into postgres schema.
i googled i got copy, but when i ran in windows
If the backup is an SQL file you just ran it with psql. If it is a DATA file, you copy it:
COPY actor FROM 'c:\users\venu\downloads\sakila-data.sql';
You are copying a .sql file, that smells fishy.
ERROR: invalid input syntax for integer: ""
CONTEXT: COPY actor, line 1, column actor_id: ""
This may be caused by
the backupdata format
COPY actor (actor_id, first_name, last_name, last_update) FROM stdin;
1PENELOPEGUINESS2006-02-15 09:34:33
2NICKWAHLBERG2006-02-15 09:34:33
3EDCHASE2006-02-15 09:34:33
4JENNIFERDAVIS2006-02-15 09:34:33
If your file includes the COPY ... from STDIN then it is definitely an SQL file, it is self contained, the copy from STDIN instructs psql to get the data lines following it until EOF or a \. is found. It is similar to which pg_dump will produce.
A data file would be just the data lines. PSQL would not understand it, but "copy from xxxx.dat" would be fine.
What is exactly in your data file ? If it includes copy from stdin, then 'psql -f data.sql' would do the trick ( add approiate database names, host, password, as needed, just the same you would use in an standard psql command, remember db name goes last ).