mysqli_stmt::send_long_data

mysqli_stmt_send_long_data

(PHP 5, PHP 7, PHP 8)

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

说明

面向对象风格

public mysqli_stmt::send_long_data(int $param_num, string $data): bool

过程化风格

mysqli_stmt_send_long_data(mysqli_stmt $statement, int $param_num, 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

statement: 仅以过程化样式：由 mysqli_stmt_init() 返回的 mysqli_stmt 对象。
param_num: 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。

示例

示例 #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

mysqli_prepare() - 预处理执行 SQL
mysqli_stmt_bind_param() - Binds variables to a prepared statement as parameters

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用户贡献的备注 3 notes

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ChrisH ¶

5 years ago

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.

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Gustavo Narea ¶

18 years ago

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.

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DimeCadmium ¶

3 years ago

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.