mysqli_stmt::send_long_data

mysqli_stmt_send_long_data

(PHP 5, PHP 7)

mysqli_stmt::send_long_data -- mysqli_stmt_send_long_data — Send data in blocks

说明

面向对象风格

mysqli_stmt::send_long_data ( int $param_nr , string $data ) : bool

过程化风格

mysqli_stmt_send_long_data ( mysqli_stmt $stmt , int $param_nr , string $data ) : bool

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.

参数

stmt

仅以过程化样式：由 mysqli_stmt_init() 返回的 statement 标识。

param_nr

Indicates which parameter to associate the data with. Parameters are numbered beginning with 0.

data

A string containing data to be sent.

返回值

成功时返回 TRUE， 或者在失败时返回 FALSE。

范例

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();
?>

参见

User Contributed Notes

ChrisH 28-Nov-2019 12:40
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.
Gustavo Narea 16-May-2006 07:00
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.
lussnig at smcc dot de 26-Oct-2005 07:31
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.