Row
This documentation reflects Arrow JS v4.0. Needs to be updated for the new Arrow API in v9.0 +.
A Row
is an Object that retrieves each value at a certain index across a collection of child Vectors. Rows are returned from the get()
function of the nested StructVector
and MapVector
, as well as RecordBatch
and Table
.
A Row
defines read-only accessors for the indices and (if applicable) names of the child Vectors. For example, given a StructVector
with the following schema:
const children = [
Int32Vector.from([0, 1]),
Utf8Vector.from(['foo', 'bar'])
];
const type = new Struct<{ id: Int32, value: Utf8 }>([
new Field('id', children[0].type),
new Field('value', children[1].type)
]);
const vector = new StructVector(Data.Struct(type, 0, 2, 0, null, children));
const row = vector.get(1);
assert((row[0] === 1 ) && (row.id === row[0]));
assert((row[1] === 'bar') && (row.value === row[1]));
Row
implements the Iterator interface, enumerating each value in order of the child vectors list.
Notes:
- If the Row's parent type is a
Struct
,Object.getOwnPropertyNames(row)
returns the child vector indices. - If the Row's parent type is a
Map
,Object.getOwnPropertyNames(row)
returns the child vector field names, as defined by thechildren
Fields list of theMap
instance.
Methods
[key: string]: T[keyof T]['TValue']
[kParent]: MapVector<T>
| StructVector<T>
[kRowIndex]: number
[kLength]: number
(readonly)
[Symbol.iterator](): IterableIterator<T[keyof T]["TValue"]>
get(key: K): T[K]["TValue"]
Returns the value at the supplied key
, where key
is either the integer index of the set of child vectors, or the name of a child Vector