# pg_lo_truncate

(PHP 5 >= 5.6.0, PHP 7)

pg_lo_truncate — Truncates a large object

### 说明

pg_lo_truncate ( resource `$large_object` , int `$size` ) : bool

pg_lo_truncate() truncates a large object resource.

To use the large object interface, it is necessary to enclose it within a transaction block.

### 参数

`large_object`

  PostgreSQL large object (LOB) resource, returned by pg_lo_open().

`size`

  The number of bytes to truncate.

### 返回值

成功时返回 `TRUE`， 或者在失败时返回 `FALSE`。

### 范例

Example #1 pg_lo_truncate() example

    <?php
       $doc_oid = 189762345;
       $database = pg_connect("dbname=jacarta");
       pg_query($database, "begin");
       $handle = pg_lo_open($database, $doc_oid, "r");
       // Truncate to 0
       pg_lo_truncate($handle, 0);
       pg_query($database, "commit");
       echo $data;
    ?>

### 更新日志

版本 | 说明
--- | ---
5.6.0 | Added truncate function. It supports PostgreSQL 9.3's 64bit large object. Both client and server must support PostgreSQL 9.3 and PHP must be 64bit build to use 64bit large object.

### 参见

- pg_lo_tell() - 返回大型对象的当前指针位置