5.6. Update

[重要項目]重要項目

To update an index entry, old one must be removed and a new one added.

Remember that a node or relationship can be associated with any number of key-value pairs in an index, which means that you can index a node or relationship with many key-value pairs that have the same key. In the case where a property value changes and you’d like to update the index, it’s not enough to just index the new value - you’ll have to remove the old value as well.

Here’s a code example for that demonstrates how it’s done:

// create a node with a property
Node fishburn = graphDb.createNode();
fishburn.setProperty( "name", "Fishburn" );
// index it
actors.add( fishburn, "name", fishburn.getProperty( "name" ) );
// update the index entry
actors.remove( fishburn, "name", fishburn.getProperty( "name" ) );
fishburn.setProperty( "name", "Laurence Fishburn" );
actors.add( fishburn, "name", fishburn.getProperty( "name" ) );