PHP8 cubrid_lob2_read

2024-03-28 09:31 更新

(PECL CUBRID >= 8.4.1)

cubrid_lob2_read — 从 BLOB/CLOB 数据读取

说明

cubrid_lob2_read(resource $lob_identifier, int $len): string

cubrid_lob2_read（）函数从 LOB 数据并返回读取的字节数。len

参数

lob_identifier: 作为 cubrid_lob2_new（）结果的 Lob 标识符或从结果集中获取。
len: 要从 lob 数据中读取的缓冲区的长度。

返回值

以字符串形式返回内容，当没有更多数据时返回 false，失败时返回 null。

示例

示例 #1 cubrid_lob2_read（） example 1

<?php
// test_lob (id INT, contents CLOB)

$conn = cubrid_connect("localhost", 33000, "demodb", "public", "");

$req = cubrid_execute($conn, "select * from test_lob");

$row = cubrid_fetch_row($req, CUBRID_LOB);

print "position now is " . cubrid_lob2_tell($row[1]) . "\n";

cubrid_lob2_seek($row[1], 10, CUBRID_CURSOR_FIRST);

print "\nposition after moving farword is " . cubrid_lob2_tell($row[1]) . "\n";

$data = cubrid_lob2_read($row[1], 12);

print "\nposition after reading is " . cubrid_lob2_tell($row[1]) . "\n";

print $data . "\n";

cubrid_lob2_seek($row[1], 5, CUBRID_CURSOR_CURRENT);

print "\nposition after moving again is " . cubrid_lob2_tell($row[1]) . "\n";

$data = cubrid_lob2_read($row[1], 20);
print $data . "\n";

cubrid_disconnect($conn);
?>

示例 #2 cubrid_lob2_read（） example 2

<?php
// test_lob (id INT, contents CLOB)

$conn = cubrid_connect("localhost", 33000, "demodb", "dba", "");

$req = cubrid_execute($conn, "select * from test_lob");

$row = cubrid_fetch_row($req, CUBRID_LOB);

while (true) {
    if ($data = cubrid_lob2_read($row[1], 1024)) {
        print $data . "\n";
    }
    elseif ($data === false) {
        print "There is no more data\n";
        break;
    }
    else {
        print "There must some errors\n";
        break;
    }
}

cubrid_disconnect($conn);
?>

参见

cubrid_lob2_write（） - 写入 lob 对象
cubrid_lob2_seek（） - 移动 lob 对象的光标
cubrid_lob2_seek64（） - 移动 lob 对象的光标
cubrid_lob2_tell（） - 告知 LOB 对象的光标位置
cubrid_lob2_tell64（） - 告知 LOB 对象的光标位置
cubrid_lob2_size（） - 获取 lob 对象的大小
cubrid_lob2_size64（） - 获取 lob 对象的大小

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