PDOStatement::getColumnMeta

    (PHP 5 >= 5.1.0, PHP 7, PHP 8, PECL pdo >= 0.2.0)

    PDOStatement::getColumnMeta — Returns metadata for a column in a result set

    Description

    public PDOStatement::getColumnMeta(int $column): array|false

    Retrieves the metadata for a 0-indexed column in a result set as an associative array.

    Warning

    Some drivers may not implement PDOStatement::getColumnMeta(), as it is optional. However, all PDO drivers documented in the manual implement this function.

    Parameters

    column

    The 0-indexed column in the result set.

    Return Values

    Returns an associative array containing the following values representing the metadata for a single column:

    Column metadata
    Name Value
    native_type The PHP native type used to represent the column value.
    driver:decl_type The SQL type used to represent the column value in the database. If the column in the result set is the result of a function, this value is not returned by PDOStatement::getColumnMeta().
    flags Any flags set for this column.
    name The name of this column as returned by the database.
    table The name of this column's table as returned by the database.
    len The length of this column. Normally -1 for types other than floating point decimals.
    precision The numeric precision of this column. Normally 0 for types other than floating point decimals.
    pdo_type The type of this column as represented by the PDO::PARAM_* constants.

    Returns false if the requested column does not exist in the result set, or if no result set exists.

    Examples

    Example #1 Retrieving column metadata

    The following example shows the results of retrieving the metadata for a single column generated by a function (COUNT) in a PDO_SQLITE driver.

    <?php
    $select     = $DB->query('SELECT COUNT(*) FROM fruit');
    $meta = $select->getColumnMeta(0);
    var_dump($meta);
    ?>

    The above example will output:

    array(6) {
  ["native_type"]=>
  string(7) "integer"
  ["flags"]=>
  array(0) {
  }
  ["name"]=>
  string(8) "COUNT(*)"
  ["len"]=>
  int(-1)
  ["precision"]=>
  int(0)
  ["pdo_type"]=>
  int(2)
}

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    User Contributed Notes 6 notes

    up
    11
    colin at fusionbox dot com
    16 years ago
    This method is supported in the MySQL 5.0+ driver.  It can be used for object hydration:<?php$pdo_stmt = $dbh->execute('SELECT discussion.id, discussion.text, comment.id, comment.text FROM discussions LEFT JOIN comments ON comment.discussion_id = discussion.id');foreach(range(0, $pdo_stmt->columnCount() - 1) as $column_index){  $meta[] = $pdo_stmt->getColumnMeta($column_index);}while($row = $pdo_stmt->fetch(PDO::FETCH_NUM)){  foreach($row as $column_index => $column_value)  {    //do something with the data, using the ids to establish the discussion.has_many(comments) relationship.  }}?>If you are building an ORM, this method is very useful to support more natural SQL syntax.  Most ORMs require the column names to be aliases so that they can be parsed and turned into objects that properly represent has_one, has_many, many_to_many relationships.
    up
    4
    asohn aircanopy net
    17 years ago
    I found a short discussion related to this function at http://www.sitepoint.com/forums/showthread.php?t=497257I haven't tried it (yet?) but hopefully someone can find it useful.
    up
    1
    Rodrigo Silva
    6 years ago
    native_type has the following mapping for MySQL:(tested in PHP 5.4, MySQL 5.7)INT(11) (PKs) => LONGTINYINT(4)    => TINYDOUBLE        => DOUBLEVARCHAR       => VAR_STRINGCHAR          => STRINGDATE          => DATEFunctions     => VAR_STRING- DATEFORMAT()- CONCAT()
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    0
    samer dot mhana at gmail dot com
    4 years ago
    Searching for LONGLONG in php-src:     $datatypes = array(        MYSQLI_TYPE_TINY => "TINY",        MYSQLI_TYPE_SHORT => "SHORT",        MYSQLI_TYPE_LONG => "LONG",        MYSQLI_TYPE_FLOAT => "FLOAT",        MYSQLI_TYPE_DOUBLE => "DOUBLE",        MYSQLI_TYPE_TIMESTAMP => "TIMESTAMP",        MYSQLI_TYPE_LONGLONG => "LONGLONG",        MYSQLI_TYPE_INT24 => "INT24",        MYSQLI_TYPE_DATE => "DATE",        MYSQLI_TYPE_TIME => "TIME",        MYSQLI_TYPE_DATETIME => "DATETIME",        MYSQLI_TYPE_YEAR => "YEAR",        MYSQLI_TYPE_ENUM => "ENUM",        MYSQLI_TYPE_SET    => "SET",        MYSQLI_TYPE_TINY_BLOB => "TINYBLOB",        MYSQLI_TYPE_MEDIUM_BLOB => "MEDIUMBLOB",        MYSQLI_TYPE_LONG_BLOB => "LONGBLOB",        MYSQLI_TYPE_BLOB => "BLOB",        MYSQLI_TYPE_VAR_STRING => "VAR_STRING",        MYSQLI_TYPE_STRING => "STRING",        MYSQLI_TYPE_NULL => "NULL",        MYSQLI_TYPE_NEWDATE => "NEWDATE",        MYSQLI_TYPE_INTERVAL => "INTERVAL",        MYSQLI_TYPE_GEOMETRY => "GEOMETRY",    );
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    0
    jcastromail at yahoo dot es
    5 years ago
    This method is supported by sql server too (at least the version of the PDO driver 5.7.1)Example:array(8) {  ["flags"]=>  int(0)  ["sqlsrv:decl_type"]=>  string(12) "int identity"  ["native_type"]=>  string(6) "string"  ["table"]=>  string(0) ""  ["pdo_type"]=>  int(2)  ["name"]=>  string(8) "IdCompra"  ["len"]=>  int(10)  ["precision"]=>  int(0)}
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    0
    frankno dot 94 at gmail dot com
    5 years ago
    I recently added a note to a small function that went through the results of PDOStatement::fetch and mapped columns to integer or float types.I forgot to test for columns that can have a null value!I'm updating the code here, sorry.This website doesn't let me edit the original comment, so I'm just gonna link to a gist in case it needs even further fixes.https://gist.github.com/AeonFr/db3b2a8a95753076d9e4da42d29365d2I basically added this code:<?phpif ($value === null) {   continue;}?>
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