pg_select

(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)

pg_select — 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 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_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。

User Contributed Notes

wietse at cj2 dot nl 27-Feb-2006 08:20


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] => 

        )

)

david dot tulloh at infaze dot com dot au 16-May-2005 09:46


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.