# Presto 316 Documentation

## 9.15. DESCRIBE INPUT

## Synopsis

    DESCRIBE INPUT statement_name

## Description

Lists the input parameters of a prepared statement along with the position and type of each parameter. Parameter types that cannot be determined will appear as `unknown`.

## Examples

Prepare and describe a query with three parameters:

    PREPARE my_select1 FROM
    SELECT ? FROM nation WHERE regionkey = ? AND name < ?;

    DESCRIBE INPUT my_select1;

     Position | Type
    --------------------
            0 | unknown
            1 | bigint
            2 | varchar
    (3 rows)

Prepare and describe a query with no parameters:

    PREPARE my_select2 FROM
    SELECT * FROM nation;

    DESCRIBE INPUT my_select2;

     Position | Type
    -----------------
    (0 rows)

## See Also

PREPARE