This will register a WP CLI command to delete Gravity form Entries

delete_gravity_form_entries.php

<?php
/**
 * Plugin Name: WP CLI commands for deleting Gravity form entries.
 * Plugin URI: https://brainstormforce.com
 * Description: Register WP CLI command to delete Gravity form entries.
 * Version: 0.0.1
 * Author: Brainstorm Force
 * Author URI: https://brainstormforce.com
 * Text Domain: bsf
 */

function bsf_delete_gf_entries( $args = array(), $assoc_args = array() ) {

    // Get arguments.
	$arguments = wp_parse_args(
		$assoc_args,
		array(
            'days_old'  => 0,
            'interval'  => 'days',
            'delete_db_entries' => false
		)
    );

    if( ! class_exists( 'GFFormsModel' ) ) {
        WP_CLI::error( 'Gravity forms plugins is not installed on this site' );
    }

    if( empty( $arguments['days_old'] ) || 0 === $arguments['days_old'] ) {
        WP_CLI::error( 'Invalid arguments. Specify --days_old parameter' );
    }

    global $wpdb;

    $results = $wpdb->get_results( "SELECT id FROM {$wpdb->prefix}gf_entry WHERE date_created < now() - interval {$arguments['days_old']} DAY", ARRAY_A );

    if( is_wp_error( $results ) ) {
        WP_CLI::error( 'Error running MySql query.' . $wpdb->last_error );
    }

    $entry_table             = GFFormsModel::get_entry_table_name();
    $entry_notes_table       = GFFormsModel::get_entry_notes_table_name();
    $entry_meta_table_name   = GFFormsModel::get_entry_meta_table_name();
    $entries_list = array();

    if( ! empty( $results ) ) {
       foreach( (array) $results as $result ) {
            $entry_id = $result['id'];

            // Deleting uploaded files
            GFFormsModel::delete_files( $entry_id );

            if( $arguments['delete_db_entries'] ) {

                // Delete from entry meta
                $sql = $wpdb->prepare( "DELETE FROM $entry_meta_table_name WHERE entry_id=%d", $entry_id );
                $wpdb->query( $sql );

                // Delete from lead notes
                $sql = $wpdb->prepare( "DELETE FROM $entry_notes_table WHERE entry_id=%d", $entry_id );
                $wpdb->query( $sql );

                // Delete from entry table
                $sql = $wpdb->prepare( "DELETE FROM $entry_table WHERE id=%d", $entry_id );
                $wpdb->query( $sql );
            }
            
            WP_CLI::line( "Deleted entry with ID " . $entry_id );

            $entries_list[] = $entry_id;
       }
    }

    WP_CLI::success( 'Sucessfully deleted '. count( $entries_list ) . ' entries with ID.' . implode( " ,", $entries_list ) );
}


if ( defined( 'WP_CLI' ) && WP_CLI ) {
	WP_CLI::add_command( 'delete-gf-entries', 'bsf_delete_gf_entries' );    
}