ResultSet

class ResultSet()

Represents the row-returning result of a Connection() query (see select() and its shorthands). Not constructed directly by applications – it’s what those methods resolve with.

Despite the name, this isn’t a real streaming implementation yet: all rows are fetched up front and held in memory. The restricted rows API below (rather than a plain Array) is forward-looking, so that a future streaming implementation won’t change how consumers iterate over results.

Properties

rowCount

ResultSet.rowCount

Type:

number

The number of rows in this result set.

totalRowCount

ResultSet.totalRowCount

Type:

number

Present only when the query used limit/skip: the total number of rows that matched, before pagination was applied.

rows

ResultSet.rows

Type:

object

An Array-like object over the result rows, deliberately restricted – see below.

Note

rows only supports rows.forEach(fn), rows.map(fn) (both async, and both iterate every row despite the name “map”/“forEach” suggesting sync usage), and rows[0] (the first row). rows.length is undefined, and accessing any other numeric index (rows[1], etc.) throws 'random access into result sets is not supported'. Use rowCount, above, for the count, and getFirst()/getNext(), below, for cursor-style access.

Methods

getFirst

getFirst()

Resets the cursor to the beginning of the result set and returns the first row (or false if there are none). This is an async method that returns a Promise.

Return type:

Promise<object|false>

getNext

getNext()

Advances the cursor and returns the next row, or false once the cursor has passed the last row. The first call to getNext() (without a prior getFirst()) returns the first row. This is an async method that returns a Promise.

Return type:

Promise<object|false>

Example

const db = await require('dcp/jnu').connect('scheduler');
const result = await db.select({ table: 'jobs', limit: 10 });

let row;
while ((row = await result.getNext()) !== false) console.log(row);