here are the data types that correspond to the TYPE number returned by fetch_field.
thought i would post this here since i couldn't find the info elsewhere.
numerics
-------------
BIT: 16
TINYINT: 1
BOOL: 1
SMALLINT: 2
MEDIUMINT: 9
INTEGER: 3
BIGINT: 8
SERIAL: 8
FLOAT: 4
DOUBLE: 5
DECIMAL: 246
NUMERIC: 246
FIXED: 246
dates
------------
DATE: 10
DATETIME: 12
TIMESTAMP: 7
TIME: 11
YEAR: 13
strings & binary
------------
CHAR: 254
VARCHAR: 253
ENUM: 254
SET: 254
BINARY: 254
VARBINARY: 253
TINYBLOB: 252
BLOB: 252
MEDIUMBLOB: 252
TINYTEXT: 252
TEXT: 252
MEDIUMTEXT: 252
LONGTEXT: 252
mysqli_result::fetch_field
mysqli_fetch_field
(PHP 5, PHP 7, PHP 8)
mysqli_result::fetch_field -- mysqli_fetch_field — Liefert die Metadaten der nächsten Spalte einer Ergebnismenge
Beschreibung
Objektorientierter Stil
Prozeduraler Stil
Gibt die Definition einer Spalte aus einer Ergebnismenge als Objekt zurück. Um Informationen über alle Spalten in der Ergebnismenge abzurufen, muss diese Funktion mehrmals aufgerufen werden.
Parameter-Liste
-
result Nur bei prozeduralem Aufruf: Ein von mysqli_query(), mysqli_store_result(), mysqli_use_result() oder mysqli_stmt_get_result() zurückgegebenes mysqli_result-Objekt.
Rückgabewerte
Gibt ein Objekt zurück, das die Informationen über die Definition einer
Spalte enthält, oder false, wenn keine Spalteninformationen verfügbar sind.
| Eigenschaft | Beschreibung |
|---|---|
| name | Der Name der Spalte |
| orgname | Der ursprüngliche Name der Spalte, falls ein Alias angegeben wurde |
| table | Der Name der Tabelle, zu der diese Spalte gehört (falls nicht berechnet) |
| orgtable | Der ursprüngliche Name der Tabelle, falls ein Alias angegeben wurde |
| def | Reserviert für den Standardwert, derzeit immer "" |
| db | Der Name der Datenbank |
| catalog | Der Name des Katalogs, immer "def" |
| max_length | Die maximale Breite der Spalte für die Ergebnismenge |
| length | Die Breite der Spalte wie in der Tabellendefinition angegeben |
| charsetnr | Die Nummer des Zeichensatzes der Spalte |
| flags | Ein Integer, der die Bit-Flags der Spalte darstellt |
| type | Der für diese Spalte verwendete Datentyp |
| decimals | Die Anzahl der verwendeten Dezimalstellen (bei Integer-Spalten) |
Beispiele
Beispiel #1 Objektorientierter Stil
<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
/* Verbindung überprüfen */
if (mysqli_connect_errno()) {
printf("Verbindung fehlgeschlagen: %s\n", mysqli_connect_error());
exit();
}
$query = "SELECT Name, SurfaceArea from Country ORDER BY Code LIMIT 5";
if ($result = $mysqli->query($query)) {
/* Informationen über alle Spalten abrufen */
while ($finfo = $result->fetch_field()) {
printf("Name: %s\n", $finfo->name);
printf("Tabelle: %s\n", $finfo->table);
printf("max. Länge: %d\n", $finfo->max_length);
printf("Flags: %d\n", $finfo->flags);
printf("Typ: %d\n\n", $finfo->type);
}
$result->close();
}
/* Verbindung schließen */
$mysqli->close();
?>Beispiel #2 Prozeduraler Stil
<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
/* Verbindung überprüfen */
if (mysqli_connect_errno()) {
printf("Verbindung fehlgeschlagen: %s\n", mysqli_connect_error());
exit();
}
$query = "SELECT Name, SurfaceArea from Country ORDER BY Code LIMIT 5";
if ($result = mysqli_query($link, $query)) {
/* Informationen über alle Spalten abrufen */
while ($finfo = mysqli_fetch_field($result)) {
printf("Name: %s\n", $finfo->name);
printf("Tabelle: %s\n", $finfo->table);
printf("max. Länge: %d\n", $finfo->max_length);
printf("Flags: %d\n", $finfo->flags);
printf("Typ: %d\n\n", $finfo->type);
}
mysqli_free_result($result);
}
/* Verbindung schließen */
mysqli_close($link);
?>Die obigen Bespiele erzeugen folgende Ausgabe:
Name: Name Tabelle: Country max. Länge: 11 Flags: 1 Typ: 254 Name: SurfaceArea Tabelle: Country max. Länge: 10 Flags: 32769 Typ: 4
Siehe auch
- mysqli_num_fields() - Ermittelt die Anzahl der Spalten in der Ergebnismenge
- mysqli_fetch_field_direct() - Ruft die Metadaten für eine einzelne Spalte ab
- mysqli_fetch_fields() - Liefert ein Array von Objekten, die die Spalten einer Ergebnismenge darstellen
- mysqli_field_seek() - Setzt den Ergebniszeiger auf die angegebene Spalte
add a note
User Contributed Notes 8 notes
iansoko at hotmail dot com ¶
12 years ago
ragtag at hotmail dot com ¶
15 years ago
The flags used by MySql are:
NOT_NULL_FLAG = 1
PRI_KEY_FLAG = 2
UNIQUE_KEY_FLAG = 4
BLOB_FLAG = 16
UNSIGNED_FLAG = 32
ZEROFILL_FLAG = 64
BINARY_FLAG = 128
ENUM_FLAG = 256
AUTO_INCREMENT_FLAG = 512
TIMESTAMP_FLAG = 1024
SET_FLAG = 2048
NUM_FLAG = 32768
PART_KEY_FLAG = 16384
GROUP_FLAG = 32768
UNIQUE_FLAG = 65536
To test if a flag is set you can use & like so:
<?php
$meta = $mysqli_result_object->fetch_field();
if ($meta->flags & 4) {
echo 'Unique key flag is set';
}
?>
andre at koethur dot de ¶
10 years ago
Here are two methods for converting the 'type' and 'flags' attributes to text for debugging purposes. They both use the predefined MYSQLI_ constants to generate the text.
<?php
public static function h_type2txt($type_id)
{
static $types;
if (!isset($types))
{
$types = array();
$constants = get_defined_constants(true);
foreach ($constants['mysqli'] as $c => $n) if (preg_match('/^MYSQLI_TYPE_(.*)/', $c, $m)) $types[$n] = $m[1];
}
return array_key_exists($type_id, $types)? $types[$type_id] : NULL;
}
public static function h_flags2txt($flags_num)
{
static $flags;
if (!isset($flags))
{
$flags = array();
$constants = get_defined_constants(true);
foreach ($constants['mysqli'] as $c => $n) if (preg_match('/MYSQLI_(.*)_FLAG$/', $c, $m)) if (!array_key_exists($n, $flags)) $flags[$n] = $m[1];
}
$result = array();
foreach ($flags as $n => $t) if ($flags_num & $n) $result[] = $t;
return implode(' ', $result);
}
?>
sofe2038 at gmail dot com ¶
6 years ago
The constants in a few other comments above appear to be inaccurate. Here are some more official references that seem quite hard to search.
The "type" attribute: https://dev.mysql.com/doc/internals/en/com-query-response.html#column-type
The "flags" attribute: https://github.com/google/mysql/blob/master/include/mysql_com.h#L133
In addition, all attributes are explained on the COM_QUERY_RESPONSE page too: https://dev.mysql.com/doc/internals/en/com-query-response.html#column-definition
rvila at revolutionvisualarts dot com ¶
7 years ago
The predefined constant values returned by the function get_predefined_constants() for:
MYSQLI_TYPE_CHAR = 1
MYSQLI _TYPE_TINYINT = 1
If the code is used to categorized the type of field use this values will of course create confusion. For example:
if($fieldtype === "CHAR"){
$field_html_attribute = "text";
$field_html_length = 1;
} elseif($fieldtype === "TINYINT") {
$field_html_attribute = "number";
$field_html_length = 1;
}
If an array is created to set the key as the numeric value and the value of that key as the the text title, TINYINT will be replaced by CHAR value. But is this process is reversed, then the code will select TINYINT if the foreach statement set to break when the numeric value of the flag equals the value of the current key as the first intance.
Base in the note added by Johnathan at http://php.net/manual/en/mysqli.field-count.php the values should be:
CHAR = 254
TINYINT = 1
But predefined function attributes the value 254 to MYSQLI_TYPE_STRING.
Just for FYI
miqrogroove at gmail dot com ¶
11 years ago
Beware the values of the predefined constants. They do not always correlate with the actual field types. For example:
MYSQLI_TYPE_BLOB: 252
MYSQLI_TYPE_TINY_BLOB: 249
MYSQLI_TYPE_MEDIUM_BLOB: 250
MYSQLI_TYPE_LONG_BLOB: 251
MySQLi will indeed return a value of 252 for a tinytext field, but as you can see, this does not correspond to the value of MYSQLI_TYPE_TINY_BLOB.
nick ¶
6 years ago
It is not possible to get the values for an enum or set field through fetch_fields(). As far as I can tell this is because it hasn't been implemented in the mysqlnd api but whatever the reason it is not possible and you must issue a query like SHOW COLUMNS directly and interrogate the result to determine them.
Incidentally you need to check the enum_flag rather than look for the enum_type to determine whether a field is enum or not. The type returned is usually some kind of string.
Anonymous ¶
12 years ago
The constants for the TYPE number returned by fetch_field are enumerated here (MYSQLI_TYPE_*):
http://php.net/manual/en/mysqli.constants.php
