Nested foreach loops - anything more efficient? - php

Question

So I've got nested foreach loops, and I'm wondering if there's a more efficient way to do this, code-wise:
foreach ($arraykey as $columnname => $value) {
foreach ($records as $field_entity_id) {
$fieldinsertloop = "('registration', 'reg_type', 0,".$field_entity_id.",".$field_entity_id.", 'und', 0,'".$value."','".$value."')";
}
$sql = "INSERT INTO " .str_replace("multi_reg", "field_data", $columnname);
$sql .= " (entity_type, bundle, deleted, revision_id, entity_id, language, delta, ".str_replace("multi_reg_", "", $columnname)."_value, ".str_replace("multi_reg_", "", $columnname)."_format)";
$sql .= " VALUES ";
$sql .= $fieldinsertloop;
db_query($sql);
}
Basically, I'm wanting to optimize for either speed and then less code written - in that order or optimally both.

Answer 1

You can squeeze a bit more performance from your loops by using the values by reference:
foreach ($arraykey as $columnname => &$value) {
Hence the &$value, but beware, every time you do something to $value after that, it will affect the original $arraykey[$columnname] value. Also, not sure you're nesting the foreach correctly. I would move the ending bracket for the nested foreach down:
// $value passed by reference
foreach ($arraykey as $columnname => &$value) {
// Pass $field_entity_id by reference
foreach ($records as &$field_entity_id) {
$fieldinsertloop = "('registration', 'reg_type', 0,".$field_entity_id.",".$field_entity_id.", 'und', 0,'".$value."','".$value."')";
$sql = "INSERT INTO " .str_replace("multi_reg", "field_data", $columnname);
$sql .= " (entity_type, bundle, deleted, revision_id, entity_id, language, delta, ".str_replace("multi_reg_", "", $columnname)."_value, ".str_replace("multi_reg_", "", $columnname)."_format)";
$sql .= " VALUES ";
$sql .= $fieldinsertloop;
db_query($sql);
} // End of nested foreach moved here
}
Another issue with your code, it appears you are using Drupal db_query() which has a much better way for inserting values. If you are, you could change your code to this:
foreach ($arraykey as $columnname => &$value) {
$table = str_replace("multi_reg", "field_data", $columnname);
$columns = array('entity_type', 'bundle', 'deleted', 'revision_id', 'entity_id', 'language', 'delta', str_replace("multi_reg_", "", $columnname).'_value', str_replace("multi_reg_", "", $columnname).'_format');
foreach ($records as &$field_entity_id) {
$values = array('registration', 'reg_type', 0, $field_entity_id, $field_entity_id, 'und', 0, $value, $value);
//Build Associative Array for Insert
for( $x = 0, $max = count($values); $x < $max; $x++ ) {
$sqlValues[$columns[$x]] = $values[$x];
}
db_insert($table)->fields($columns)->values($sqlValues)->execute();
}
}
OR
foreach ($arraykey as $columnname => &$value) {
$table = str_replace("multi_reg", "field_data", $columnname);
$columns = array('entity_type', 'bundle', 'deleted', 'revision_id', 'entity_id', 'language', 'delta', str_replace("multi_reg_", "", $columnname).'_value', str_replace("multi_reg_", "", $columnname).'_format');
$query = db_insert($table)->fields($columns);
foreach ($records as &$field_entity_id) {
$values = array('registration', 'reg_type', 0, $field_entity_id, $field_entity_id, 'und', 0, $value, $value);
//Build Associative Array for Insert
for( $x = 0, $max = count($values); $x < $max; $x++ ) {
$sqlValues[$columns[$x]] = $values[$x];
}
$query->values($sqlValues);
}
$query->execute();
}
The second example should be faster, but with more lines. It waits until all the values have been added before executing. Using db_insert() requires that the values be in an associative array, with the column names as keys.
How's that for clean?