a function to generate bulk insert sql query for PDO.

bulk_insert.php

<?php

function createBulkInsertSql($sql, $rowCount, $columnSize = 1) {
    $rowCount = intval($rowCount);
    $columnSize = intval($columnSize);
    $columnMarker = array_fill(0, $columnSize, '?');
    $rowValues = array_fill(0, $rowCount, '(' . implode(',', $columnMarker) . ')');
    $sql .= ' VALUES' . implode(',', $rowValues);
    return $sql;
}

$sql = 'INSERT INTO table(column1, column2)';
$data = array(
    'column1.a', 'column2.a',
    'column1.b', 'column2.b',
    'column1.c', 'column2.c'
);
echo createBulkInsertSql($sql, 10, 2);

// INSERT INTO table(column1, column2) VALUES(?,?),(?,?),(?,?),(?,?),(?,?),(?,?),(?,?),(?,?),(?,?),(?,?)