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.
(PHP 5, PHP 7, PHP 8)
mysqli_stmt::send_long_data -- mysqli_stmt_send_long_data — Send data in blocks
面向对象风格
$param_num
, string $data
) : bool过程化风格
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.
stmt仅以过程化样式：由 mysqli_stmt_init() 返回的 statement 标识。
param_numIndicates which parameter to associate the data with. Parameters are numbered beginning with 0.
dataA string containing data to be sent.
成功时返回 true， 或者在失败时返回 false。
Example #1 面向对象风格
<?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();
?>
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.
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.
send_long_data() these function is normaly used to store Data in Binary blob field. But if the table is UTF8 and connection charset it does not expect binary data (for example images) it take utf8 Data.
This mean you have to do utf8_encode bevore sending binary data.