fbsql_read_blob()

(PHP 4 >= 4.2.0, PHP 5, PHP 7)

Read a BLOB from the database

说明

fbsql_read_blob(string $blob_handle[,resource $link_identifier]): string

Reads BLOB data from the database.

If a select statement contains BLOB and/or CLOB columns FrontBase will return the data directly when data is fetched. This default behavior can be changed with fbsql_set_lob_mode() so the fetch functions will return handles to BLOB and CLOB data. If a handle is fetched a user must call fbsql_read_blob() to get the actual BLOB data from the database.

参数

$blob_handle

A BLOB handle, returned by fbsql_create_blob().

$link_identifier

由fbsql_connect()或fbsql_pconnect()返回的 FrontBase 链接标识符.

如可选并未指定，函数会尝试查找一个到 FrontBase 服务器的开放链接，且如没有找到这样的链接，会尝试通过不带参数调用fbsql_connect()来创建一个。

返回值

Returns a string containing the specified BLOB data.

范例

Example #1 fbsql_read_blob() example

<?php
$link = fbsql_pconnect("localhost", "_SYSTEM", "secret")
    or die("Could not connect");
$sql = "SELECT BLOB_COLUMN FROM BLOB_TABLE;";
$rs = fbsql_query($sql, $link);
$row_data = fbsql_fetch_row($rs);
// $row_data[0] will now contain the blob data for the first row
fbsql_free_result($rs);
$rs = fbsql_query($sql, $link);
fbsql_set_lob_mode($rs, FBSQL_LOB_HANDLE);
$row_data = fbsql_fetch_row($rs);
// $row_data[0] will now contain a handle to the BLOB data in the first row
$blob_data = fbsql_read_blob($row_data[0]);
fbsql_free_result($rs);
?>

参见

• fbsql_create_blob()Create a BLOB
• fbsql_read_clob()Read a CLOB from the database
• fbsql_set_lob_mode()Set the LOB retrieve mode for a FrontBase result set