Passing sql parameters to copy_export

[karunpoudel-chr]

Since copy_export and copy_to accepts sql query to export the data, one may want to pass parameters similar to vars parameter in cursor.execute() function.

e.g.

cur.copy_expert(
    "COPY (select col1, col2 from test where id between %(from)s and %(to)s) TO STDOUT WITH CSV HEADER",
    file,
    vars={"from":1, "to":10}
)

[dvarrazzo]

You can use psycopg2.sql. Something like, untested:

cur.copy_expert(
    sql.SQL("COPY (select col1, col2 from test where id between {from} and {to}) TO STDOUT WITH CSV HEADER").format(from=sql.Literal(1), to=sql.Literal(10)),
    file,
)