pg_update

(PHP 4 >= 4.3.0, PHP 5, PHP 7)

pg_update — 更新表

说明

pg_update ( resource $connection , string $table_name , array $data , array $condition [, int $options = PGSQL_DML_EXEC ] ) : mixed

pg_update() 用 condition 作为条件查询数据库，用 data 中的数据更新符合条件的记录。如果指定了 options，则 pg_convert() 会按照指定选项作用到 data 上。

Warning

此函数是实验性的。此函数的表象，包括名称及其相关文档都可能在未来的 PHP 发布版本中未通知就被修改。使用本函数风险自担。

参数

connection: PostgreSQL database connection resource.
table_name: Name of the table into which to update rows.
data: An array whose keys are field names in the table table_name, and whose values are what matched rows are to be updated to.
condition: An array whose keys are field names in the table table_name, and whose values are the conditions that a row must meet to be updated.
options: Any number of PGSQL_CONV_OPTS, PGSQL_DML_NO_CONV, PGSQL_DML_EXEC or PGSQL_DML_STRING combined. If PGSQL_DML_STRING is part of the options then query string is returned.

返回值

成功时返回 TRUE，或者在失败时返回 FALSE。 Returns string if PGSQL_DML_STRING is passed via options.

范例

Example #1 pg_update() example


<?php 
  $db = pg_connect('dbname=foo');
  $data = array('field1'=>'AA', 'field2'=>'BB');
  
  // This is safe, since $_POST is converted automatically
  $res = pg_update($db, 'post_log', $_POST, $data);
  if ($res) {
      echo "Data is updated: $res\n";
  } else {
      echo "User must have sent wrong inputs\n";
  }
?>

参见

pg_convert() - 将关联的数组值转换为适合 SQL 语句的格式。

User Contributed Notes

dominik dot bonsch at homesono dot de 25-Jan-2008 01:24


Using pg_update() and pg_insert() without key validation is not secure! 



You need to check which data pairs you get, and if you want to allow to updated this column. 



Example: 



You have a table with tree colums: username, password, userlevel. 



Your users may change only their username, and their password but not their userlevel.



If you don't filter the keys in the request array, every user can now change his userlevel just by sending a POST Request with "userlevel=>100".



So if you don't check if the key are allowed in your request array you'll get serious sql injection vulnarabilities in your code.

jhooks 13-Apr-2006 07:54


> Return Values

> 

> Returns TRUE on success or FALSE on failure. Returns string if 

> PGSQL_DML_STRING is passed via options. 



I have found in my copy of PHP (version 4.4.0) that if you use the 'PGSQL_DML_STRING' option, the function does not execute any query.  It merely returns the query which would have been executed.  



Another thing I noticed, pg_update does not seem to make use of pg_trace (atleast in 4.4.0).



PS this isn't a bug report, just an explanation of some undocumented features I noticed.  As the manual says, the function is still in development so this behaviour may differ from version to version.

sdibb at myway dot com 14-Jun-2005 07:26


This function is similar to PEAR::DB's autoExecute() function, with the only difference being that the where clause is an array instead of a string.



Also, if you want to use your instance of the DB class with this function, you can reference the existing resource connection with $db->connection.



An example would be:

<?

     pg_update($db->connection, $arr_update, $arr_where);

?>