Not to be created directly from its constructor, the Query is returned from Client#query. It functions primarily as an EventEmitter allowing you to handle returned rows.

• events
  • row
  • error
  • end

Emitted by the query whenever a row is received from the PostgreSQL server upon query execution, the event listeners are passed the parsed, type-coerced row .

    var query = client.query('SELECT name, age as user_age FROM users');
    query.on('row', function(row) {
      console.log('user "%s" is %d years old', row.name, row.user_age);
    });

Emitted by the query when an error is encountered within the context of query execution, the event listeners are passed the error event from the PostgreSQL server.

If the Query object was created with an optional callback function, the error event will not fire. This prevents you from having to handle the error both in the callback function and on the event listener.

note: If this event (or any event with the name 'error') is not handled it will propagate to the global event loop. This can potentially crash your node process. This is standard node.js behavior..

    var query = client.query('SELECT asdfasdfasdf');
    query.on('error', function(error) {
      //handle the error
    });

    var query = client.query('SELECT LAKJDLSKJF', function(err, result) {
      //err is the error returned from the PostgreSQL server
      //handle the error here
    });
    query.on('error', function() {
      //this code will never execute
      assert.ok(false, "This will never be called because you supplied the optional query callback function");
    })

Emitted by the query when all rows have been returned or when an error has been encountered. In either circumstance, the query's execution is finished and it is no longer interacting with the connection.

'''javascript var query = client.query('select name from person'); query.on('row', function(row) { //fired once for each row returned }); query.on('end', function() { //fired once and only once, after the last row has been returned and after all 'row' events are emitted })

## Prepared statements

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