[PHP-DOC] PDOStatement::fetchAll update

Fri, 05 Nov 2010 12:13:34 -0700 

Hello everyone,
I've done some polishing to the PDOStatement::fetchAll documentation. Attached is the patch, as well as the resulting chunked-render html. 

Summary:


Changed the fetch_argument parameter type to mixed, as it differs per 
fetch_style, and removed the initializer.


Changed a few instances of <literal> to <constant> where appropriate.


Clarified wording of PDO::FETCH_CLASS behaviour for the fetch_argument 
parameter.


Added the PDO::FETCH_FUNC behavior for the fetch_argument parameter.

Added two examples, for PDO::FETCH_CLASS and PDO::FETCH_FUNC styles.

Thanks,
Justin Martin, a.k.a. FrozenFire

Index: en/reference/pdo/pdostatement/fetchall.xml
===================================================================
--- en/reference/pdo/pdostatement/fetchall.xml	(revision 305106)
+++ en/reference/pdo/pdostatement/fetchall.xml	(working copy)
@@ -12,7 +12,7 @@
   <methodsynopsis>
    <type>array</type><methodname>PDOStatement::fetchAll</methodname>
    <methodparam choice="opt"><type>int</type><parameter>fetch_style</parameter><initializer>PDO::FETCH_BOTH</initializer></methodparam>
-   <methodparam choice="opt"><type>int</type><parameter>fetch_argument</parameter><initializer>0</initializer></methodparam>
+   <methodparam choice="opt"><type>mixed</type><parameter>fetch_argument</parameter></methodparam>
    <methodparam choice="opt"><type>array</type><parameter>ctor_args</parameter><initializer>array()</initializer></methodparam>
   </methodsynopsis>
 
@@ -31,19 +31,19 @@
       </para>
       <para>
        To return an array consisting of all values of a single column from
-       the result set, specify <literal>PDO::FETCH_COLUMN</literal>. You
+       the result set, specify <constant>PDO::FETCH_COLUMN</constant>. You
        can specify which column you want with the
        <parameter>column-index</parameter> parameter.
       </para>
       <para>
        To fetch only the unique values of a single column from the result set,
-       bitwise-OR <literal>PDO::FETCH_COLUMN</literal> with
-       <literal>PDO::FETCH_UNIQUE</literal>.
+       bitwise-OR <constant>PDO::FETCH_COLUMN</constant> with
+       <constant>PDO::FETCH_UNIQUE</constant>.
       </para>
       <para>
        To return an associative array grouped by the values of a specified
-       column, bitwise-OR <literal>PDO::FETCH_COLUMN</literal> with
-       <literal>PDO::FETCH_GROUP</literal>.
+       column, bitwise-OR <constant>PDO::FETCH_COLUMN</constant> with
+       <constant>PDO::FETCH_GROUP</constant>.
       </para>
      </listitem>
     </varlistentry>
@@ -62,10 +62,16 @@
         </listitem>
         <listitem>
          <para>
-          <constant>PDO::FETCH_CLASS</constant>: Sets a custom class name for which 
-           the fetch results will be stored in.
+          <constant>PDO::FETCH_CLASS</constant>: Returns instances of the specified
+          class, mapping the columns of each row to named properties in the class.
          </para>
         </listitem>
+        <listitem>
+         <para>
+          <constant>PDO::FETCH_FUNC</constant>: Returns the results of calling the
+          specified function, using each row's columns as parameters in the call.
+         </para>
+        </listitem>
        </itemizedlist>
       </para>
      </listitem>
@@ -229,7 +235,91 @@
 ]]>
     </screen>
    </example>
+   <example><title>Instantiating a class for each result</title>
+    <para>
+     The following example demonstrates the behaviour of the
+     <constant>PDO::FETCH_CLASS</constant> fetch style.
+    </para>
+    <programlisting role="php">
+<![CDATA[
+<?php
+class fruit {
+ public $name;
+ public $colour;
+}
 
+$sth = $dbh->prepare("SELECT name, colour FROM fruit");
+$sth->execute();
+
+$result = $sth->fetchAll(PDO::FETCH_CLASS, "fruit");
+var_dump($result);
+?>
+]]>
+    </programlisting>
+    &example.outputs;
+    <screen>
+<![CDATA[
+array(3) {
+  [0]=>
+  object(fruit)#1 (2) {
+    ["name"]=>
+    string(5) "apple"
+    ["colour"]=>
+    string(5) "green"
+  }
+  [1]=>
+  object(fruit)#2 (2) {
+    ["name"]=>
+    string(4) "pear"
+    ["colour"]=>
+    string(6) "yellow"
+  }
+  [2]=>
+  object(fruit)#3 (2) {
+    ["name"]=>
+    string(10) "watermelon"
+    ["colour"]=>
+    string(4) "pink"
+  }
+}
+]]>
+    </screen>
+   </example>
+   <example><title>Calling a function for each result</title>
+    <para>
+     The following example demonstrates the behaviour of the
+     <constant>PDO::FETCH_FUNC</constant> fetch style.
+    </para>
+    <programlisting role="php">
+<![CDATA[
+<?php
+function fruit($name, $colour) {
+ return "{$name}: {$colour}";
+}
+
+$sth = $dbh->prepare("SELECT name, colour FROM fruit");
+$sth->execute();
+
+$result = $sth->fetchAll(PDO::FETCH_FUNC, "fruit");
+var_dump($result);
+?>
+]]>
+    </programlisting>
+    &example.outputs;
+    <screen>
+<![CDATA[
+array(3) {
+  [0]=>
+  string(12) "apple: green"
+  [1]=>
+  string(12) "pear: yellow"
+  [2]=>
+  string(16) "watermelon: pink"
+}
+]]>
+    </screen>
+   </example>
+
   </para>
  </refsect1>
 

Title: PHP Manual: Returns an array containing all of the result set rows







    

        

 

        
        
            



 

  
PDOStatement->fetchAll

  

   Returns an array containing all of the result set rows
  

 

 

  
Description

  

   array PDOStatement::fetchAll
    ([ int $fetch_style = PDO::FETCH_BOTH
   [, mixed $fetch_argument
   [, array $ctor_args = array()
  ]]] )



 



 

  
Parameters

  

   


    


     fetch_style
     


      

       Controls the contents of the returned array as documented in
       PDOStatement::fetch.
      

      

       To return an array consisting of all values of a single column from
       the result set, specify PDO::FETCH_COLUMN. You
       can specify which column you want with the
       column-index parameter.
      

      

       To fetch only the unique values of a single column from the result set,
       bitwise-OR PDO::FETCH_COLUMN with
       PDO::FETCH_UNIQUE.
      

      

       To return an associative array grouped by the values of a specified
       column, bitwise-OR PDO::FETCH_COLUMN with
       PDO::FETCH_GROUP.
      

     


    

    


     fetch_argument
     


      

       This argument have a different meaning depending on the value of 
       the fetch_style parameter:
       
    
        
  • 
         
    
          PDO::FETCH_COLUMN: Returns the indicated 0-indexed 
           column.
         
    
        
    • 
        
  • 
         
    
          PDO::FETCH_CLASS: Returns instances of the specified
          class, mapping the columns of each row to named properties in the class.
         
    
        
    • 
        
  • 
         
    
          PDO::FETCH_FUNC: Returns the results of calling the
          specified function, using each row's columns as parameters in the call.
         
    
        
    • 
       

      

     


    

    


     ctor_args
     


      

       Arguments of custom class constructor when the fetch_style 
       parameter is PDO::FETCH_CLASS.
      

     


    

   


  

 



 

  
Return Values

  

   PDOStatement::fetchAll returns an array containing
   all of the remaining rows in the result set. The array represents each
   row as either an array of column values or an object with properties
   corresponding to each column name.
  

  

   Using this method to fetch large result sets will result in a heavy
   demand on system and possibly network resources. Rather than retrieving
   all of the data and manipulating it in PHP, consider using the database
   server to manipulate the result sets. For example, use the WHERE and
   SORT BY clauses in SQL to restrict results before retrieving and
   processing them with PHP.
  

 



 

  
Examples

  

   
Example #1 Fetch all remaining rows in a result set

    



<?php
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();

/* Fetch all of the remaining rows in the result set */
print("Fetch all of the remaining rows in the result set:\n");
$result = $sth->fetchAll();
print_r($result);
?>



    


    
The above example will output:

    


Fetch all of the remaining rows in the result set:
Array
(
    [0] => Array
        (
            [NAME] => pear
            [0] => pear
            [COLOUR] => green
            [1] => green
        )

    [1] => Array
        (
            [NAME] => watermelon
            [0] => watermelon
            [COLOUR] => pink
            [1] => pink
        )

)


    

   

   
Example #2 Fetching all values of a single column from a result set

    

     The following example demonstrates how to return all of the values of a
     single column from a result set, even though the SQL statement itself
     may return multiple columns per row.
    

    



<?php
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();

/* Fetch all of the values of the first column */
$result = $sth->fetchAll(PDO::FETCH_COLUMN, 0);
var_dump($result);
?>



    


    
The above example will output:

    


Array(3)
(
    [0] =>
    string(5) => apple
    [1] =>
    string(4) => pear
    [2] =>
    string(10) => watermelon
)


    

   

   
Example #3 Grouping all values by a single column

    

     The following example demonstrates how to return an associative array
     grouped by the values of the specified column in the result set. The
     array contains three keys: values apple and
     pear are returned as arrays that contain two
     different colours, while watermelon is
     returned as an array that contains only one colour.
    

    



<?php
$insert = $dbh->prepare("INSERT INTO fruit(name, colour) VALUES (?, ?)");
$insert->execute(array('apple', 'green'));
$insert->execute(array('pear', 'yellow'));

$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();

/* Group values by the first column */
var_dump($sth->fetchAll(PDO::FETCH_COLUMN|PDO::FETCH_GROUP));
?>



    


    
The above example will output:

    


array(3) {
  ["apple"]=>
  array(2) {
    [0]=>
    string(5) "green"
    [1]=>
    string(3) "red"
  }
  ["pear"]=>
  array(2) {
    [0]=>
    string(5) "green"
    [1]=>
    string(6) "yellow"
  }
  ["watermelon"]=>
  array(1) {
    [0]=>
    string(5) "green"
  }
}



    

   

   
Example #4 Instantiating a class for each result

    

     The following example demonstrates the behaviour of the
     PDO::FETCH_CLASS fetch style.
    

    



<?php
class fruit {
 public $name;
 public $colour;
}

$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();

$result = $sth->fetchAll(PDO::FETCH_CLASS, "fruit");
var_dump($result);
?>



    


    
The above example will output:

    


array(3) {
  [0]=>
  object(fruit)#1 (2) {
    ["name"]=>
    string(5) "apple"
    ["colour"]=>
    string(5) "green"
  }
  [1]=>
  object(fruit)#2 (2) {
    ["name"]=>
    string(4) "pear"
    ["colour"]=>
    string(6) "yellow"
  }
  [2]=>
  object(fruit)#3 (2) {
    ["name"]=>
    string(10) "watermelon"
    ["colour"]=>
    string(4) "pink"
  }
}


    

   

   
Example #5 Calling a function for each result

    

     The following example demonstrates the behaviour of the
     PDO::FETCH_FUNC fetch style.
    

    



<?php
function fruit($name, $colour) {
 return "{$name}: {$colour}";
}

$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();

$result = $sth->fetchAll(PDO::FETCH_FUNC, "fruit");
var_dump($result);
?>



    


    
The above example will output:

    


array(3) {
  [0]=>
  string(12) "apple: green"
  [1]=>
  string(12) "pear: yellow"
  [2]=>
  string(16) "watermelon: pink"
}


    

   


  

 



 

  
See Also

  

   
    
    
  • PDO::query
    • 
    
  • PDOStatement::fetch
    • 
    
  • PDOStatement::fetchColumn
    • 
    
  • PDO::prepare
    • 
    
  • PDOStatement::setFetchMode
    • 
   

  

 




        		
    


























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