获取时Mysql PDO最大LONGBLOB数据长度 [英] Mysql PDO maximum LONGBLOB data length on fetch

问题描述

我将大约 1.1 Mb 的数据插入到 LONGBLOB 类型的 Mysql 字段中.这与 LONGBLOB 字段支持的最大长度相差甚远.

I insert about 1.1 Mb of Data into a Mysql Field of type LONGBLOB. This is far away from the maximum supported length of a LONGBLOB field.

插入似乎有效.

如果我在插入之前执行 strlen($data) 返回 1059245.

If I do a strlen($data) before inserting it returns 1059245.

如果我在插入后进行查询:

If i do a query after inserting:

SELECT OCTET_LENGTH(`data`)...

返回 1059245

但是如果我这样做

$stmt = $pdo->prepare("SELECT `data` FROM `tbl_mytable` WHERE `id` = :id LIMIT 1");
$stmt->bindValue(":id", $id, PDO::PARAM_INT);
$stmt->execute();
$data = $stmt->fetch(PDO::FETCH_ASSOC);
echo strlen($data['data']);

返回 1048576

我的数据似乎在 1048576 字节后被截断了.

My data seems to be cutten after 1048576 bytes.

为什么我在查询时只收到数据的前 1048576 个字节?

Why do I only receive the first 1048576 bytes of my data when doing a query?

它是 PDO 配置，类似于 max_fetch_length 吗?

Is it a PDO Configuration, something like max_fetch_length?

推荐答案

MYSQL_ATTR_MAX_BUFFER_SIZE 默认为 1MB.

It was the MYSQL_ATTR_MAX_BUFFER_SIZE which is 1MB by default.

这解决了问题:

    $pdo->setAttribute(PDO::MYSQL_ATTR_MAX_BUFFER_SIZE, 1024*1024*50);  // 50 MB      

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