Migrating from Posts 2 Posts

If you use the Posts 2 Posts (P2P) plugin, you can migrate relationship data to Native Content Relationships.

Comparison

• P2P uses a custom table and defines “connection types” with direction and cardinality.
• NCR uses a single relations table and “relation types” with from/to object types and optional max_connections.

Approach

1. Map connection types — For each P2P connection type, define an NCR relation type (same or similar name) with ncr_register_relation_type. Map P2P “from”/“to” post types to NCR from/to (use post for any post type unless you need user/term).
2. Export P2P data — P2P stores rows in its table (e.g. p2p_id, p2p_from, p2p_to, p2p_type). Use a SQL export or P2P’s API to get (from_id, to_id, type).
3. Import — For each row, call ncr_add_relation( $from_id, 'post', $to_id, 'post', $mapped_type ). Handle duplicate prevention if your script runs multiple times.
4. Replace code — Replace P2P API calls with ncr_get_related and WP_Query using content_relation. Update templates and any P2P-specific shortcodes or blocks to NCR equivalents.
5. Deactivate P2P — After verification, deactivate and optionally uninstall P2P.

Copy-paste migration example

Step 1 — Export P2P data. If you have DB access, you can export (from the P2P table, e.g. wp_p2p) rows with p2p_from, p2p_to, p2p_type. Save to a CSV or PHP array.

Step 2 — Map P2P type to NCR type. Register the NCR type if needed (see Custom types), e.g. map P2P my_connection → NCR my_connection.

Step 3 — Import. Example: you have an array of rows [ 'from' => id, 'to' => id, 'type' => 'my_connection' ].

<?php
// migrate-p2p-to-ncr.php — run once. $p2p_rows = your exported data.
if ( ! function_exists( 'ncr_add_relation' ) ) {
	return;
}
$p2p_rows = [ /* e.g. from DB or CSV: [ ['from'=>123,'to'=>456,'type'=>'my_connection'], ... ] */ ];
$type_map = [ 'my_connection' => 'my_connection' ]; // P2P type => NCR type

foreach ( $p2p_rows as $row ) {
	$ncr_type = $type_map[ $row['type'] ] ?? $row['type'];
	$from = (int) $row['from'];
	$to   = (int) $row['to'];
	if ( $from && $to && get_post_status( $from ) && get_post_status( $to ) ) {
		ncr_add_relation( $from, 'post', $to, 'post', $ncr_type );
	}
}

Before (P2P): p2p_get_related_posts( $post_id, 'my_connection' ) or similar.
After (NCR): ncr_get_related( $post_id, 'post', 'my_connection' ) and WP_Query with content_relation.

Notes

• P2P supports multiple connection types per pair; NCR supports multiple relation types. Map each P2P connection type to one NCR relation type.
• Run wp content-relations check and spot-check front-end and admin before removing P2P.