Pass Parameters to Queries

Why query with parameters?

Cypher supports querying with parameters. This simplifies query reuse and makes caching of execution plans easier, in turn leading to faster query execution times.

Parameters as map

The Bolt.Sips module allows us to pass our parameters as a map in a third argument to the query/3 function. (The first argument is the database connection, and the second is the query string.)

But the query functions we have created so far just take the query string and implicitly supply the database connection. We need to do something about that.

Parameters support

Let’s add some functionality to support querying with parameters.

Add callbacks

We’ll first update the GraphCommons.Service behavior with a couple of optional callbacks: