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.
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
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.
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
add a note
User Contributed Notes 4 notes
Gustavo Narea ¶
18 years ago
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.
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.
lussnig at smcc dot de ¶
19 years ago
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.
