mysql_field_flags

(PHP 4, PHP 5)

mysql_field_flagsRetourne des détails sur une colonne MySQL

Avertissement

Cette extension est obsolète depuis PHP 5.5.0, et sera supprimée dans le futur. À la place, les extensions MySQLi ou PDO_MySQL doivent être utilisées. Voir aussi le guide MySQL : choix de l'API ainsi que la FAQ associée pour plus d'information. Voici les alternatives à cette fonction :

Description

string mysql_field_flags ( resource $result , int $field_offset )

mysql_field_flags() retourne le sémaphore associé au champ spécifié par field_offset, dans le résultat result. Les sémaphores sont retournés comme des mots, séparés par des espaces, ce qui les rend faciles à séparer, avec la commande explode().

Liste de paramètres

result

La ressource de résultat qui vient d'être évaluée. Ce résultat vient de l'appel à la fonction mysql_query().

field_offset

La position numérique du champ. field_offset commence à 0. Si field_offset n'existe pas, une alerte E_WARNING sera également générée.

Valeurs de retour

Retourne les sémaphores sous la forme d'une chaîne associés avec le résultat ou FALSE si une erreur survient.

Les valeurs suivantes (pour une version suffisamment récente de MySQL) sont disponibles : "not_null", "primary_key", "unique_key", "multiple_key", "blob", "unsigned", "zerofill", "binary", "enum", "auto_increment" et "timestamp".

Exemples

Exemple #1 Exemple avec mysql_field_flags()

<?php
$result 
mysql_query("SELECT id,email FROM people WHERE id = '42'");
if (!
$result) {
   echo 
'Impossible d\'exécuter la requête : ' mysql_error();
   exit;
}
$flags mysql_field_flags($result0);

echo 
$flags;
print_r(explode(' '$flags));
?>

L'exemple ci-dessus va afficher quelque chose de similaire à :

not_null primary_key auto_increment
Array
(
   [0] => not_null
   [1] => primary_key
   [2] => auto_increment
)

Notes

Note:

Pour des raisons de compatibilité ascendante, l'alias obsolète suivant peut être utilisé : mysql_fieldflags()

Voir aussi

add a note add a note

User Contributed Notes 10 notes

up
1
pike-php at kw dot nl
9 years ago
ok, sorry for the code bloat :) but this is how I
get the full power of mysql's DESCRIBE table statement, in
an associative array, including defaults, enum values, float radix et all.

it assumes mysql returns the type as
   "type[(arg[,arg..])] [ add]"
like
   "float(20,6) unsigned"
   "enum('yes','no')"
etc

<?

function getFields($tablename) {
   
        $fields = array();
        $fullmatch         = "/^([^(]+)(\([^)]+\))?(\s(.+))?$/";
        $charlistmatch     = "/,?'([^']*)'/";
        $numlistmatch     = "/,?(\d+)/";
       
        $fieldsquery .= "DESCRIBE $tablename";
        $result_fieldsquery = mysql_query($fieldsquery) or die(mysql_error());
        while ($row_fieldsquery = mysql_fetch_assoc($result_fieldsquery)) {
           
            $name     = $row_fieldsquery['Field'];
            $fields[$name] = array();
            $fields[$name]["type"]         = "";
            $fields[$name]["args"]         = array();
            $fields[$name]["add"]          = "";
            $fields[$name]["null"]        = $row_fieldsquery['Null'];
            $fields[$name]["key"]        = $row_fieldsquery['Key'];
            $fields[$name]["default"]    = $row_fieldsquery['Default'];
            $fields[$name]["extra"]        = $row_fieldsquery['Extra'];
           
            $fulltype     = $row_fieldsquery['Type'];
            $typeregs = array();
           
            if (preg_match($fullmatch, $fulltype, $typeregs)) {
                $fields[$name]["type"] = $typeregs[1];
                if ($typeregs[4]) $fields[$name]["add"] = $typeregs[4];
                $fullargs = $typeregs[2];
                $argsreg = array();
                if (preg_match_all($charlistmatch, $fullargs, $argsreg)) {
                    $fields[$name]["args"] = $argsreg[1];
                } else {
                    $argsreg = array();
                    if (preg_match_all($numlistmatch, $fullargs, $argsreg)) {
                        $fields[$name]["args"] = $argsreg[1];
                    } else die("cant parse type args: $fullargs");
                }
            } else die("cant parse type: $fulltype");

        }
        return $fields;
           
    }

?>
up
1
amir at scrounch dot com
11 years ago
returns primary keys of a table using 'show keys'
although it is possible to use desc, show keys offers possible enhancements such a getting sequence in index along with it

function getPrimaryKeyOf($table, $link) {
  $pk = Array();

  $sql = 'SHOW KEYS FROM `'.$table.'`';
  $res = mysql_query($table, $link) or die(mysql_error());
  while ($row = mysql_fetch_assoc($res)) {
    if ($row['Key_name']=='PRIMARY')
      array_push($pk, $row['Column_name']);
  }
  return $pk;
}
up
1
jakemsr at jakemsr dot com
12 years ago
I didn't find anything to get the valid values for
ENUM or SET column types, so I came up with the
following

function mysql_enum_values($table, $field)
{
    $sql = "SHOW COLUMNS FROM $table LIKE '$field'";
    $sql_res = mysql_query($sql)
        or die("Could not query:\n$sql");
    $row = mysql_fetch_assoc($sql_res);
    mysql_free_result($sql_res);
    return(explode("','",
        preg_replace("/.*\('(.*)'\)/", "\\1",
            $row["Type"])));
}
up
1
cufarley at nirvanet dot net
13 years ago
Using the "DESC TableName" command may also do the trick and is a bit shorter.
up
0
play at arcadevillage dot com
5 years ago
To really backup the database values, I made a little changement :

My code really looks like bomas 's code, but there is an important diffence :

<?php
$nbc
= mysql_num_fields($req_table);
while (
$ligne = mysql_fetch_array($req_table))
  {
   
$insertions = "INSERT INTO $table VALUES(";
     for (
$i=0; $i<$nbc; $i++)
        {
          if (
$i > 0 ) $insertions .= ", ";
          if ( !isset(
$ligne[$i]))
           
$insertions .= "NULL";
          else
           
$insertions .= "'" . mysql_real_escape_string($ligne[$i]). "'";
        }
    
$insertions .= ");";
    
$dumpsql[] = $insertions;
   }
?>

$dumpslq is the variable where I put the insertion orders before writting them in a text file.

Before, I test that the values if not NULL into the field because it is the only way to make the difference, for example for string text fields, between NULL values and empty strings.

If you don't make this test, you should find empty string instead of NULL values when you do the backup.
up
0
buttrose at unimelb dot edu dot au
10 years ago
This function is essential for writing a generic table editor (ie one that just takes the name of the table and works out what fields it has, types, sizes etc.). Unfortunately, I am using psotgreSQL not mySql. Postgres has field_type and field_size functions  but not as far as I can tell an equivalent of the mysql_field_flags() function. Without it, there is no way I can do generic ADDs and INSERTs.

Anyone know a workaround to get this information (eg is the field a primary key? Can it be NULL? Is it auto_increment?) in Postgres?

Cheers

Rob Buttrose
up
0
justin DOT flavin AT ntlworld DOT com
11 years ago
Sometimes, when writing a generic function or class, you want your script to be able to determine what the primary key of a table is.
/* usual MySQL stuff */
$query="DESC UsersTable";
$results=mysql_query($query);

while ($row=mysql_fetch_array($results))
{
if ($row[Type]="PRI")
    {
print "I found the primary key! <br>";
$UserKey=$row[Field];
print $row[Field];
/* drop out , as we've found the key */   
exit;
    }
}

..... later on we might have something like

< some sort of loop through records >

print "<a href='View_User_record.php?userkey=$UserKey'> Users Name </a>";

<end loop>

What's also interesting is the useful data you can get from
a DESC query.

The following prints out the array values grabbed by mysql_fetch_array on a DESC query - VERY useful stuff!!!

/* usual MySQL stuff */
$query="DESC UsersTable";
$results=mysql_query($query);

while ($row=mysql_fetch_array($results))
{
print "<pre>";
print_r ($row);
print "</pre>";
}
up
-1
bomas at cities-of-faith dot com
9 years ago
well, to make a complete backup of your database, i suggest this code:

//open database here
$tab_status = mysql_query("SHOW TABLE STATUS");
while($all = mysql_fetch_assoc($tab_status)):
    $tbl_stat[$all[Name]] = $all[Auto_increment];
endwhile;
unset($backup);
$tables = mysql_list_tables('cofadmin');
while($tabs = mysql_fetch_row($tables)):
    $backup .= "--\n--Tabel structuur voor `$tabs[0]`\n--\n\nDROP IF EXISTS TABLE `$tabs[0]`\nCREATE TABLE IF NOT EXISTS `$tabs[0]` (&nbsp;";
    $res = mysql_query("SHOW CREATE TABLE $tabs[0]");
    while($all = mysql_fetch_assoc($res)):
        $str = str_replace("CREATE TABLE `$tabs[0]` (", "", $all['Create Table']);
        $str = str_replace(",", ",&nbsp;", $str);
        $str2 = str_replace("`) ) TYPE=MyISAM ", "`)\n ) TYPE=MyISAM ", $str);
        $backup .= $str2." AUTO_INCREMENT=".$tbl_stat[$tabs[0]].";\n\n";
    endwhile;
    $backup .= "--\n--Gegevens worden uitgevoerd voor tabel `$tabs[0]`\n--\n\n";
    $data = mysql_query("SELECT * FROM $tabs[0]");
    while($dt = mysql_fetch_row($data)):
        $backup .= "INSERT INTO `$tabs[0]` VALUES('$dt[0]'";
        for($i=1; $i<sizeof($dt); $i++):
            $backup .= ", '$dt[$i]'";
        endfor;
        $backup .= ");\n";
    endwhile;
    $backup .= "\n-- --------------------------------------------------------\n\n";
endwhile;
echo $backup;

this displayes your data the same way as phpmyadmin does.

hope it helps some of you guys
Greetz
up
-1
simone dot t at betisgroup dot com
11 years ago
Another examples :

####################################

function field_keys($host, $user, $password, $database, $field ) {
   $db_link = mysql_connect($host, $user, $password) or die ("error connect");
   mysql_select_db($database,$db_link);
   $query="DESC $field";
   $results=mysql_query($query);
   $i=0;
   while ($row=mysql_fetch_array($results)) {
         if ($row[Key]=="PRI") {
            $array_keys[$i]=$row[Field];
         }
         $i++;
  }
   return $array_keys;
}

####################################

//Example of Main...
$tmp = field_keys("localhost", "myuser", "mypassword", "mydb", "field_name" );

// ...loop through array...
foreach ( $tmp as $array_tmp){
    print "<br>";
    print $array_tmp;
    print "<br>";
}
up
-2
jurgen at alienguitar dot com
13 years ago
The previous problem to get the default values of a column:
Use the following query and parse the 'Default' column:

"SHOW COLUMNS FROM TableName"

or for a single entry:

"SHOW COLUMNS FROM TableName LIKE 'column'"

It will give you also values for Type,  Null, Key and Extra (check with mysql program first, so you see what you get ;-)
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