Inserting a large number of iterative rows in a mysql database - php

Question

I need to add bulk data to my table 'wp_usermeta'. The data is the same but with just the user_id changing for every row. A PHP example would be:
for($i = 1; $i < 10000; $i++){
mysql_query(
"INSERT INTO wp_usermeta ('user_id', 'meta_key', 'meta_value')
VALUES ($i, "key", "value")");
}
So I'm adding one row for every user up to 10,000 users which is exactly the same except for the user_id which is taken from the iteration variable.
Is there any way to do this more efficiently in mysql?

Answer 1

This will do it in one SQL statement:
$sql="
INSERT INTO wp_usermeta ('user_id', 'meta_key', 'meta_value')
VALUES
";
for($i = 1; $i < 10000; $i++){
$sql.="($i, 'key', 'value'),";
}
$sql=rtrim($sql, ",");
Please don't use the deprecated mysql_ functions, use mysqli_ or PDO instead.

Answer 2

There's no way to avoid an INSERT statement for each row, however, if you do them all at once (in a single query), it will be faster than doing them separately:
INSERT INTO wp_usermeta (user_id, meta_key, meta_value)
VALUES (1, 'key', 'value'),
VALUES (2, 'key', 'value'),
...
VALUES (10000, 'key', 'value');
MySQL updates indexes after each query completes. Here, it's one query, so the indexes are only updated after all of the rows are inserted.
Even doing the inserts separately, but with a prepared statement and bound parameters, would be faster than your current method.

Answer 3

You could do it with this statement:
INSERT INTO wp_usermeta (user_id, meta_key, meta_value)
SELECT
nums.n, 'key', 'value'
FROM (
SELECT
a.N + b.N * 10 + c.N * 100 + +d.N * 1000 + 1 AS n
FROM
(SELECT 0 AS N UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) a
,(SELECT 0 AS N UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) b
,(SELECT 0 AS N UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) c
,(SELECT 0 AS N UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) d
ORDER BY n
) nums;
Explanation
The inner select builds the numbers from 1 to 10.000
Demo

Answer 4

Try this code
<?php
$query = "INSERT INTO wp_usermeta ('user_id', 'meta_key', 'meta_value') VALUES ";
$user_details = array();
for($i = 1; $i < 10000; $i++){
$user_details[] = "(".$i.",'key','value')";
}
$query .= implode(",", $user_details);
mysql_query($query);
?>