Select

Basically, get records

By key

By key :

$df->select()->record(key: 42); // Return record array

// equivalent to
$df->getRecord(key: 42);

// equivalent to
$df[42];

Traversable

Both dataframe and select statement object are traversable to iterate records. Have a look to corresponding documentation.

The Select Statement

The Select object represents a statement to explore au subset of data corresponding to selection and doing stats with them. You can build them using a SQL-like constructor. They offer some commodity helpers methods to modify or extract directly the selected data, but it's not its main purpose.

The three different types of Select statements

$df->select('colA', 'colB'): Select // Return Select
$df->selectAll(): SelectAll // With all columns, and keep the  selection in returned select object even if columns are aded or deleted to the dataframe.
$df->col('colA'): ColumnRepresentation // A classic select with extra methods to rename, remove, clone, type the selected column.

Extract from a Select Statement

Return the result as a new DataFrame object:

$newDf = $df->select('colA','colC')->whereColumn('colB', equal: 42)->export();

Or directly to an array:

$newArr = $stmt->toArray();

// equivalent to (but slower)
$newArr = $stmt->export()->toArray();