To read data from a Parquet file, use the read_parquet function in the FROM clause of a query:

SELECT * FROM read_parquet('input.parquet'); 

Alternatively, you can omit the read_parquet function and let DuckDB infer it from the extension:

SELECT * FROM 'input.parquet'; 

To create a new table using the result from a query, use CREATE TABLE ... AS SELECT statement:

CREATE TABLE new_tbl AS SELECT * FROM read_parquet('input.parquet'); 

To load data into an existing table from a query, use INSERT INTO from a SELECT statement:

INSERT INTO tbl SELECT * FROM read_parquet('input.parquet'); 

Alternatively, the COPY statement can also be used to load data from a Parquet file into an existing table:

COPY tbl FROM 'input.parquet' (FORMAT PARQUET); 

For additional options, see the Parquet loading reference.