Best multiInsert way to add database in php? - php

Question

How is best way add to database multiInsert row?
E.g I have array and i would like add all array to database. I can create loop foreach and add all arrays.
$array=['apple','orange'];
foreach($array as $v)
{
$stmt = $db->exec("Insert into test(fruit) VALUES ('$v')");
}
And it's work, but maybe i should use transaction? or it do other way?

Answer 1

Use a prepared statement.
$sql = "INSERT INTO test (fruit) VALUES ";
$sql .= implode(', ', array_fill(0, count($array), '(?)'));
$stmt = $db->prepare($sql);
$stmt->execute($array);
The SQL will look like:
INSERT INTO test (fuit) VALUES (?), (?), (?), ...
where there are as many (?) as the number of elements in $array.
Doing a single query with many VALUES is much more efficient that performing separate queries in a loop.
If you have an associative array with input values for a single row, you can use a prepared query like this:
$columns = implode(',', array_keys($array);
$placeholders = implode(', ', array_fill(0, count($array), '?'));
$sql = "INSERT INTO test($columns) VALUES ($placeholders)";
$stmt = $db->prepare($sql);
$stmt->execute(array_values($array));

Answer 2

The way you've done it is, in many ways, the worst option. So the good news is that any other way of doing it will probably be better. As it stands, the code may fail depending on what's in the data; consider:
$v="single ' quote";
$stmt = $db->exec("Insert into test(fruit) VALUES ('$v')");
But without knowing what your criteria are for "best", its rather hard to advise. Using a parametrised query with data binding, or as they are often described "prepared statements" is one solution to the problem described above. Escaping the values appropriately before interpolating the string is another (and is how most PHP implementations of data binding work behind the scenes) is another common solution.
Leaving aside the question of how you get the parameters into the SQL statement, then there is the question of performance. Each round trip to the database has a cost associated with it. And doing a single insert at a time also has a performance impact - for each query, the DBMS must parse the query, apply the appropriate concurrency controls, execute the query, apply the writes to the journal, then to the data tables and indexes then tidy up before it can return the thread of execution back to PHP to construct the next query.
Wrapping multiple queries in a transaction (you are using transactions already - but they are implicit and applied to each statement) can reduce some of the overhead I have described here, but can introduce other problems, the nature of which depends on which concurrency model your DBMS uses.
To get the data into the database as quickly as possible, and minimising index fragmentation, the "best" solution is to batch up multiple inserts:
$q="INSERT INTO test (fruit) VALUES ";
while (count($array)) {
$s=$q;
$j='';
for ($x=0; $x<count($array) && $x<CHUNKSIZE; $x++) {
$s.=$j." ('" . mysqli_real_escape_string($db,
array_shift($array)) . "')";
$j=',';
}
mysqli_query($db,$s);
}
This is similar to Barmar's method, but I think easier to understand when you are working with more complex record structures, and it won't break with very large input sets.