mysql_field_flags
(PHP 4, PHP 5)
mysql_field_flags — Get the flags associated with the specified field in a result
This extension is deprecated as of PHP 5.5.0, and will be removed in the future. Instead, the MySQLi or PDO_MySQL extension should be used. See also MySQL: choosing an API guide and related FAQ for more information. Alternatives to this function include:
- mysqli_fetch_field_direct() [flags]
- PDOStatement::getColumnMeta() [flags]
Description
$result
, int $field_offset
)mysql_field_flags() returns the field flags of the specified field. The flags are reported as a single word per flag separated by a single space, so that you can split the returned value using explode().
Parameters
-
result -
The result resource that is being evaluated. This result comes from a call to mysql_query().
-
field_offset -
The numerical field offset. The
field_offsetstarts at 0. Iffield_offsetdoes not exist, an error of levelE_WARNINGis also issued.
Return Values
Returns a string of flags associated with the result or FALSE on failure.
The following flags are reported, if your version of MySQL is current enough to support them: "not_null", "primary_key", "unique_key", "multiple_key", "blob", "unsigned", "zerofill", "binary", "enum", "auto_increment" and "timestamp".
Examples
Example #1 A mysql_field_flags() example
<?php
$result = mysql_query("SELECT id,email FROM people WHERE id = '42'");
if (!$result) {
echo 'Could not run query: ' . mysql_error();
exit;
}
$flags = mysql_field_flags($result, 0);
echo $flags;
print_r(explode(' ', $flags));
?>
The above example will output something similar to:
not_null primary_key auto_increment
Array
(
[0] => not_null
[1] => primary_key
[2] => auto_increment
)
Notes
Note:
For backward compatibility, the following deprecated alias may be used: mysql_fieldflags()
See Also
- mysql_field_type() - Get the type of the specified field in a result
- mysql_field_len() - Returns the length of the specified field
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Коментарии
The previous problem to get the default values of a column:
Use the following query and parse the 'Default' column:
"SHOW COLUMNS FROM TableName"
or for a single entry:
"SHOW COLUMNS FROM TableName LIKE 'column'"
It will give you also values for Type, Null, Key and Extra (check with mysql program first, so you see what you get ;-)
Using the "DESC TableName" command may also do the trick and is a bit shorter.I didn't find anything to get the valid values for
ENUM or SET column types, so I came up with the
following
function mysql_enum_values($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"])));
}
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 ($row);
print "</pre>";
}
Another examples :
####################################
function field_keys($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 $array_tmp;
print "<br>";
}
returns primary keys of a table using 'show keys'
although it is possible to use desc, show keys offers possible enhancements such a getting sequence in index along with it
function getPrimaryKeyOf($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 $pk;
}
This function is essential for writing a generic table editor (ie one that just takes the name of the table and works out what fields it has, types, sizes etc.). Unfortunately, I am using psotgreSQL not mySql. Postgres has field_type and field_size functions but not as far as I can tell an equivalent of the mysql_field_flags() function. Without it, there is no way I can do generic ADDs and INSERTs.
Anyone know a workaround to get this information (eg is the field a primary key? Can it be NULL? Is it auto_increment?) in Postgres?
Cheers
Rob Buttrose
ok, sorry for the code bloat :) but this is how I
get the full power of mysql's DESCRIBE table statement, in
an associative array, including defaults, enum values, float radix et all.
it assumes mysql returns the type as
"type[(arg[,arg..])] [ add]"
like
"float(20,6) unsigned"
"enum('yes','no')"
etc
<?
function getFields($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;
}
?>
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]` ( ";
$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(",", ", ", $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
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.