pg_select

(PHP 4 >= 4.3.0, PHP 5)

pg_select — Select records

說明

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

pg_select() selects records specified by assoc_array which has field=>value. For a successful query, it returns an array containing all records and fields that match the condition specified by assoc_array.

If options is specified, pg_convert() is applied to assoc_array with the specified flags.

參數

connection: PostgreSQL database connection resource.
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_ESCAPE, 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. When PGSQL_DML_NO_CONV or PGSQL_DML_ESCAPE is set, it does not call pg_convert() internally.

回傳值

如果成功則回傳 TRUE，失敗則回傳 FALSE。 Returns string if PGSQL_DML_STRING is passed via options.

範例

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";
  }
?>

更新日誌

版本	說明
5.6.0	No longer experimental. Added `PGSQL_DML_ESCAPE` constant, `TRUE`/`FALSE` and `NULL` data type support.
5.5.3/5.4.19	Direct SQL injection to `table_name` and Indirect SQL injection to identifiers are fixed.

參見

pg_convert() - Convert associative array values into suitable for SQL statement

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User Contributed Notes 2 notes

down

david dot tulloh at infaze dot com dot au ¶

18 years ago


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.

down

-5

wietse at cj2 dot nl ¶

18 years ago


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] => 
        )
)

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