pg_select()

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

选择记录

说明

pg_select(resource $connection,string $table_name,array $assoc_array[,int $options= PGSQL_DML_EXEC]): mixed

pg_select()根据assoc_array数组中的field=>value值来选择记录。成功的查询返回和assoc_array指定的条件相匹配的包括记录和字段的数组。

如果指定了options，pg_convert()会按照指定选项作用于assoc_array之上。

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 数据库连接资源。

$table_name

Name of the table from which to select rows.

$assoc_array

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 retrieved.

$options

Any number of PGSQL_CONV_FORCE_NULL,PGSQL_DML_NO_CONV,PGSQL_DML_EXEC,PGSQL_DML_ASYNC or PGSQL_DML_STRING combined. If PGSQL_DML_STRING is part of the$optionsthen 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_select() example

<?php 
  $db = pg_connect('dbname=foo');
  // This is safe, since $_POST is converted automatically
  $rec = pg_select($db, 'post_log', $_POST);
  if ($rec) {
      echo "Records selected\n";
      var_dump($rec);
  } 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。

Valid options are PGSQL_DML_NO_CONV, PGSQL_DML_EXEC, PGSQL_DMP_ASYNC, PGSQL_DML_STRING (pulled out of source code).
This function does not support selecting from multiple tables. You can get around this by setting the PGSQL_DML_NO_CONV option. This prevents the error which occurs when the function tries to convert the condition array.
I think it is also important to point out that the table_name field is not safe, particularily with the PGSQL_DML_NO_CONV option.
The arguements array field is compulsory, as documented. What isn't so clear is that the array has to actually have some values in it, you can't do a select all.
In summary, this function is good for a very small subset of basic queries. If you are after anything more complex you are better off with pg_query.

David mentioned that you can't do a Select all.
However, when executing this script:
<?php
  $conn_string = "dbname=mydb";
  $db = pg_connect($conn_string);
  $selectfields = array("imgid" => "");
  $records = pg_select($db,"mmsfiles",$selectfields);
  print_r($records);
?>
...I get this result:
Array
(
  [0] => Array
    (
      [imgid] => 1
      [file] => /home/wietse/public_html/mms/images/1.gif
      [thumb] => 
    )
  [1] => Array
    (
      [imgid] => 2
      [file] => /home/wietse/public_html/mms/images/2.gif
      [thumb] => 
    )
  [2] => Array
    (
      [imgid] => 3
      [file] => /home/wietse/public_html/mms/images/3.gif
      [thumb] => 
    )
  [3] => Array
    (
      [imgid] => 4
      [file] => /home/wietse/public_html/mms/images/4.gif
      [thumb] => 
    )
)