Mysql Multi-Value Inserts with PHP and PDO

Mysql allows you to issue a single INSERT query with multiple records at once. This can be more efficient than single row inserts in a loop, especially when the database server is several milliseconds of round-trip-time away.

INSERT INTO database.tablename 
(field1, field2)
(val1_1, val1_2),
(val2_1, val2_2),
(val_3_1, val3_2)

It’s not so obvious how to accomplish a similar kind of query when using PDO in php while maintaining save query practices. Here I share a solution I had to devise recently to solve this problem. It is presented as a function that takes 5 arguments:

//This block is not valid php. I've written it this way to better illustrate the 
//variable types.
PDO $db; //the PDO database handle to use.

// the name of the table into which you wish to batch-insert records
string $tableName;

string[] $fieldList; //the list of fields you will be setting.

a two-dimensional array of records. Each entry in the array is itself an associative array which represents a table row. The keys of the rows must match the entries in the $fieldList you supplied above.
array<array<string,string>> $valueList;

how many rows you wish to insert for each query execution. Dial this up or down to improve efficiency at the cost of a bigger query. The maximum number will depend on your system parameters.
int $batchSize = 50; 

Here is the code

function multiInsert(PDO $db, string $tableName, array $fieldList, array& $valueList, int $batchSize = 25): bool
        if (mb_stripos($tableName, '.') === false) {
            throw new Exception('You must supply a fully qualified table name.');

        if ($batchSize <= 1) {
            throw new Exception('batchSize must be at least 2');

        //generate the INSERT query
        $insertFieldClause = implode(",\n", $fieldList);

        $queryPrefix = "INSERT INTO {$tableName} (

        $fieldCount = count($fieldList);

        $valueCount = count($valueList);

        if ($valueCount === 0) {
            throw new Exception('valueList cannot be empty');

        $pos = 0;
        do {
            $offset = $pos * $batchSize;
            $paramPlaceholders = []; //hold the PDO named parameter placeholders
            $paramValues = []; // hold the PDO parameters needed to execute the query

            for ($i = $offset; $i < ($offset + $batchSize); $i++) {
                $row = $valueList[$i];

                if ($i >= $valueCount) { //stop once you've exhausted the values list.

                $singleRow = [];
                foreach ($fieldList as $field) {
                    if (!is_string($field)){
                        throw new Exception('Field names must be strings');

                    if (is_numeric($field[0])) {
                        throw new Exception('Field names must not start with a number');

                    if (!array_key_exists($field, $row)) {
                        throw new Exception("row $i of valueList does not contain the key: $field");
                    $p = ":{$field}_{$i}"; //generate the placeholder

                        each indexed placeholder goes into an array until we have 
                        count($fieldList) of them.
                    $singleRow[]= "$p";
                    $paramValues[$p] = $row[$field];
                /* flatten the placeholders into the expected string format for 
                a mysql query value_list
                see for
                 guidance on the syntax.*/
                $iv  = "\n(" . implode(",\n", $singleRow) . ")";
                /* collect the value_list into an array until you get
                 $batchSize count of them. */
                $paramPlaceholders[] = $iv; 

                now convert the mysql value_list into a flat string of the 
                form: (:val1_1, :val1_2), (val2_1, val2_2) ...
                implode() is a handy way of doing this.
            $valuesClause = implode(",\n", $paramPlaceholders);

            //concatenate the query prefix with the value_list we just constructed.

            $query = $queryPrefix . ' VALUES ' . $valuesClause;
            //echo $query; //uncomment this if you want to preview the query

            //prepare and execute!

        } while ($pos < ceil($valueCount / $batchSize));

        return true;


//suppose the function is called with fieldList and valueList as below:
$fieldList = [

$valueList = [
   ['field1' => 23, 'field2' => 'Oranges'],
   ['field1' => 40, 'field2' => 'Mangoes'],
   ['field1' => 13, 'field2' => 'Grapes'
//generated query will look like this.
INSERT INTO database.tableName (
(:field1_0, :field2_0),
(:field1_1, :field2_1),
(:field1_2, :field2_2)

//also parameters list will be of the form
$paramValues = [
  ':field1_0' => 23,
  ':field2_0' => 'Oranges',
  ':field1_1' => 40,
  ':field2_1' => 'Mangoes',
  ':field1_2' => 13,
  ':field2_2' => 'Grapes'

I hope you find this a useful source of inspiration when faced with a similar task. Let me know in the comments if you spot a mistake.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

This site uses cookies, mainly to provide basic functionality and some analytics (so that I can see how busy the site is, and which pages are popular). By continuing to use this site, you have agreed to the use of cookies. You can close this window/tab if you do not wish to browse this site.