(PHP 5, PHP 7, PHP 8)
mysqli_stmt::send_long_data -- mysqli_stmt_send_long_data — Send data in blocks
Object-oriented style
Procedural style
Allows to send parameter data to the server in pieces (or chunks), e.g. if the
size of a blob exceeds the size of max_allowed_packet.
This function can be called multiple times to send the parts of a character or
binary data value for a column, which must be one of the TEXT or BLOB datatypes.
statementProcedural style only: A mysqli_stmt object returned by mysqli_stmt_init() .
param_numIndicates which parameter to associate the data with. Parameters are numbered beginning with 0.
dataA string containing data to be sent.
Example #1 Object-oriented style
<?php
$stmt = $mysqli->prepare("INSERT INTO messages (message) VALUES (?)");
$null = NULL;
$stmt->bind_param("b", $null);
$fp = fopen("messages.txt", "r");
while (!feof($fp)) {
$stmt->send_long_data(0, fread($fp, 8192));
}
fclose($fp);
$stmt->execute();
?>
If you are trying to write a single field which is above max_allowed_packet then this function will not help you (contrary to what the documentation example seems to show above).
Parameters in MySQL are still restricted by max_allowed_packet on a per-field basis so you will get an error like:
"mysqli_sql_exception: Parameter of prepared statement which is set through mysql_send_long_data() is longer than 'max_long_data_size' bytes"
The only real use case for this function seems to be if you are writing multiple long fields which when combined would go over max_allowed_packet.Just in case:
'max_allowed_packet' is a MySQL variable; it is not a PHP function/variable/constant.
Further info: http://dev.mysql.com/doc/refman/4.1/en/packet-too-large.html
HTH.To ChrisH's note, you must call this function multiple times with the same $param_nr, to send the first max_allowed_packet bytes, then the next, and so on. So you might need to do a for loop over changing substr() indexes, or etc.