Queries in OrientJS

Where the features described in previous chapters operate through their own API's, OrientJS handles queries as a series of methods tied to the Database API. Once you've initialized the variable for your database, (here called db), you can execute queries through it to get data from OrientDB.

There are two methods available in issuing queries to the database. You can query it directly in SQL. Alternatively, you can use the Query Builder methods to construct your query in Node.js.

Working with Queries

When querying the database directly, you prepare a string containing OrientDB SQL, then pass it to either the db.query() or db.exec() methods. For instance, going back to the baseball database, say that you want a list of players with a batting average of at least .300 that played for the Red Sox.

db.query(
   'SELECT name, ba FROM Player '
   + 'WHERE ba >= 0.3 AND team = "Red Sox"'
).then(function(hitters){
   console.log(hitters)
});

Using Parameters

In the event that you want to query other teams and batting averages, such as the case where you want your application to serve a website, you can use previously defined variables, (here, targetBA and targetTeam), to set these parameters. You can also add a limit to minimize the amount of data your application needs to parse.

Do not enclose param placeholders in single/double quotes in query string. Query parameters are properly encoded by their type. Given example below, the executed query will be SELECT name, ba FROM Player WHERE ba >= 0.3 AND team = "Red Sox" LIMIT 20

var targetBA = 0.3;
var targetTeam = 'Red Sox';

db.query(
   'SELECT name, ba FROM Player '
   + 'WHERE ba >= :ba AND team = :team',
   {params:{
            ba: targetBA,
            team: targetTeam
           },
    limit: 20
   }
).then(function(hitters){
   console.log(hitters)
});

Query Builder

Rather than writing out query strings in SQL, you can alternatively use the OrientJS Query Builder to construct queries using a series of methods connected through the Database API.