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mysql_field_flags — Liefert die Flags eines Feldes in einem Anfrageergebnis
mysql_field_flags() liefert die Flags des Feldes mit dem übergebenen Offset. Die Flags werden als einzelne Worte pro Flag und durch ein einziges Leerzeichen getrennt geliefert, so dass sie leicht mit explode() getrennt werden können.
Die folgenden Flags werden geliefert, wenn Ihre Version von MySQL diese unterstützt: "not_null", "primary_key", "unique_key", "multiple_key", "blob", "unsigned", "zerofill", "binary", "enum", "auto_increment", "timestamp".
Beispiel #1 Ein mysql_field_flags() Beispiel
<?php
$result = mysql_query("SELECT id,email FROM people WHERE id = '42'");
if (!$result) {
echo 'Abfrage konnte nicht ausgeführt werden: ' . mysql_error();
exit;
}
$flags = mysql_field_flags($result, 'id');
print $flags;
print_r(explode(' ', $flags));
/* Die Ausgabe wird so ähnlich aussehen:
not_null primary_key auto_increment
Array
(
[0] => not_null
[1] => primary_key
[2] => auto_increment
)
*/
?>
Für Abwärtskompatibilität kann mysql_fieldflags() verwendet werden. Diese Funktion ist jedoch veraltet.
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;
}
?>
$dumpslq is the variable where I put the insertion orders before writting them in a text file.
Before, I test that the values if not NULL into the field because it is the only way to make the difference, for example for string text fields, between NULL values and empty strings.
If you don't make this test, you should find empty string instead of NULL values when you do the backup.
To parse an enum/set type correctly, including strings like ENUM('a\'b','c'), here is an almost pcre-free way that works well.
<?php
function parse_enum_values($typestr)
{
// remove ENUM/SET part
$typestr = preg_replace('/^(enum|set)/i', '', $typestr);
// trim '(', ')', ' off the ends of the string and then explode it on ','
return trim(explode("','", $typestr), "(')");
}
?>
It works because explode is looking for ',' - not ',\'.
With regard to get_fields() by pike-php at kw dot nl
For 'enum and 'set' the code improperly parses single quote marks that should be allowed in the elements.
For example EMUM('a\'s', 'b') is parsed into 3 array elements when it should be 2.
Wrong:
[args] => Array
(
[0] => a
[1] => s
[2] => b
)
It should give:
[args] => Array
(
[0] => a's
[1] => b
)
I am not good with preg, but if someone could provide a solution, that would be great. Thank you!
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 $backup;
this displayes your data the same way as phpmyadmin does.
hope it helps some of you guys
Greetz
ok, sorry for the code bloat :) but this is how I
get the full power of mysql's DESCRIBE table statement, in
an associative array, including defaults, enum values, float radix et all.
it assumes mysql returns the type as
"type[(arg[,arg..])] [ add]"
like
"float(20,6) unsigned"
"enum('yes','no')"
etc
<?
function getFields($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 $fields;
}
?>
This function is essential for writing a generic table editor (ie one that just takes the name of the table and works out what fields it has, types, sizes etc.). Unfortunately, I am using psotgreSQL not mySql. Postgres has field_type and field_size functions but not as far as I can tell an equivalent of the mysql_field_flags() function. Without it, there is no way I can do generic ADDs and INSERTs.
Anyone know a workaround to get this information (eg is the field a primary key? Can it be NULL? Is it auto_increment?) in Postgres?
Cheers
Rob Buttrose
returns primary keys of a table using 'show keys'
although it is possible to use desc, show keys offers possible enhancements such a getting sequence in index along with it
function getPrimaryKeyOf($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 $pk;
}
Another examples :
####################################
function field_keys($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>";
}
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 ($row);
print "</pre>";
}
I didn't find anything to get the valid values for
ENUM or SET column types, so I came up with the
following
function mysql_enum_values($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"])));
}
Using the "DESC TableName" command may also do the trick and is a bit shorter.
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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