CascadiaPHP 2024

mysql_list_tables

(PHP 4, PHP 5)

mysql_list_tablesList tables in a MySQL database

Aviso

Esta função tornou-se defasada a partir do PHP 4.3.0 e ela e a extensão MySQL original foram removidas a partir do PHP 7.0.0. Em vez disso, use as extensões MySQLi ou PDO_MySQL, que são desenvolvidas ativamente. Veja também o guia MySQL: escolhendo uma API. Alternativas a esta função incluem:

  • SQL Query: SHOW TABLES FROM dbname

Descrição

mysql_list_tables(string $database, resource $link_identifier = NULL): resource|false

Retrieves a list of table names from a MySQL database.

This function is deprecated. It is preferable to use mysql_query() to issue an SQL SHOW TABLES [FROM db_name] [LIKE 'pattern'] statement instead.

Parâmetros

database

The name of the database

link_identifier

A conexão MySQL. Se o identificador da conexão não for especificado, a última conexão aberta por mysql_connect() será usada. Se não houver uma conexão anterior, haverá uma tentativa de criar uma como se mysql_connect() tivesse sido chamada sem argumentos. Se nenhuma conexão for encontrada ou estabelecida, um erro de nível E_WARNING será gerado.

Valor Retornado

A result pointer resource on success ou false em caso de falha.

Use the mysql_tablename() function to traverse this result pointer, or any function for result tables, such as mysql_fetch_array().

Registro de Alterações

Versão Descrição
4.3.7 This function became deprecated.

Exemplos

Exemplo #1 mysql_list_tables() alternative example

<?php
$dbname
= 'mysql_dbname';

if (!
mysql_connect('mysql_host', 'mysql_user', 'mysql_password')) {
echo
'Could not connect to mysql';
exit;
}

$sql = "SHOW TABLES FROM $dbname";
$result = mysql_query($sql);

if (!
$result) {
echo
"DB Error, could not list tables\n";
echo
'MySQL Error: ' . mysql_error();
exit;
}

while (
$row = mysql_fetch_row($result)) {
echo
"Table: {$row[0]}\n";
}

mysql_free_result($result);
?>

Notas

Nota:

Para compatibilidade com versões anteriores, o seguinte apelido defasado pode ser usado: mysql_listtables()

Veja Também

add a note

User Contributed Notes 13 notes

up
1
daveheslop (dave heslop)
19 years ago
Worth noting for beginners: using a row count to test for the existence of a table only works if the table actually contains data, otherwise the test will return false even if the table exists.
up
0
kroczu at interia dot pl
17 years ago
<?
// here is a much more elegant method to check if a table exists ( no error generate)

if( mysql_num_rows( mysql_query("SHOW TABLES LIKE '".$table."'")))
{
//...
}

?>
up
0
NewToPHP_Guy at Victoria dot NOSPAM dot com
21 years ago
The example by PHP-Guy to determine if a table exists is interesting and useful (thanx), except for one tiny detail. The function 'mysql_list_tables()' returns table names in lower case even when tables are created with mixed case. To get around this problem, add the 'strtolower()' function in the last line as follows:

return(in_array(strtolower($tableName), $tables));
up
-1
daevid at daevid dot com
21 years ago
I was in need of a way to create a database, complete with tables from a .sql file. Well, since PHP/mySQL doesn't allow that it seems, the next best idea was to create an empty template database and 'clone & rename it'. Guess what? There is no mysql_clone_db() function or any SQL 'CREATE DATABASE USING TEMPLATEDB' command. grrr...

So, this is the hack solution I came up with:

$V2DB = "V2_SL".$CompanyID;

$result = mysql_create_db($V2DB, $linkI);
if (!$result) $errorstring .= "Error creating ".$V2DB." database<BR>\n".mysql_errno($linkI).": ".mysql_error($linkI)."<BR>\n";

mysql_select_db ($V2DB, $linkI) or die ("Could not select ".$V2DB." Database");

//You must have already created the "V2_Template" database.
//This will make a clone of it, including data.

$tableResult = mysql_list_tables ("V2_Template");
while ($row = mysql_fetch_row($tableResult))
{
$tsql = "CREATE TABLE ".$V2DB.".".$row[0]." AS SELECT * FROM V2_Template.".$row[0];
echo $tsql."<BR>\n";
$tresult = mysql_query($tsql,$linkI);
if (!$tresult) $errorstring .= "Error creating ".$V2DB.".".$row[0]." table<BR>\n".mysql_errno($linkI).": ".mysql_error($linkI)."<BR>\n";
}
up
-2
bimal at sanjaal dot com
11 years ago
A better alternative to mysql_list_tables() would be the following mysql_tables() function.

<?php
/**
* Better alternative to mysql_list_tables (deprecated)
*/
function mysql_tables($database='')
{
$tables = array();
$list_tables_sql = "SHOW TABLES FROM {$database};";
$result = mysql_query($list_tables_sql);
if(
$result)
while(
$table = mysql_fetch_row($result))
{
$tables[] = $table[0];
}
return
$tables;
}

# Usage example
$tables = mysql_tables($database_local);
?>
up
-3
thebitman at attbi dot com
21 years ago
okay everybody, the fastest, most accurate, safest method:

function mysql_table_exists($table, $link)
{
$exists = mysql_query("SELECT 1 FROM `$table` LIMIT 0", $link);
if ($exists) return true;
return false;
}

Note the "LIMIT 0", I mean come on, people, can't get much faster than that! :)
As far as a query goes, this does absolutely nothing. But it has the ability to fail if the table doesnt exist, and that's all you need!
up
-3
mrkvomail at centrum dot cz
18 years ago
You can also do this with function mysql_query(). It's better because mysql_list_tables is old function and you can stop showing errors.

function mysql_table_exists($dbLink, $database, $tableName)
{
$tables = array();
$tablesResult = mysql_query("SHOW TABLES FROM $database;", $dbLink);
while ($row = mysql_fetch_row($tablesResult)) $tables[] = $row[0];
if (!$result) {
}
return(in_array($tableName, $tables));
}
up
-3
Anonymous
21 years ago
<?
/*
Function that returns whole size of a given MySQL database
Returns false if no db by that name is found
*/

function getdbsize($tdb) {
$db_host='localhost';
$db_usr='USER';
$db_pwd='XXXXXXXX';
$db = mysql_connect($db_host, $db_usr, $db_pwd) or die ("Error connecting to MySQL Server!\n");
mysql_select_db($tdb, $db);

$sql_result = "SHOW TABLE STATUS FROM " .$tdb;
$result = mysql_query($sql_result);
mysql_close($db);

if($result) {
$size = 0;
while ($data = mysql_fetch_array($result)) {
$size = $size + $data["Data_length"] + $data["Index_length"];
}
return $size;
}
else {
return FALSE;
}
}

?>

<?
/*
Implementation example
*/

$tmp = getdbsize("DATABASE_NAME");
if (!$tmp) { echo "ERROR!"; }
else { echo $tmp; }
?>
up
-3
Anonymous
18 years ago
Getting the database status:
<?
// Get database status by DtTvB
// Connect first
mysql_connect ('*********', '*********', '********');
mysql_select_db ('*********');

// Get the list of tables
$sql = 'SHOW TABLES FROM *********';
if (!$result = mysql_query($sql)) { die ('Error getting table list (' . $sql . ' :: ' . mysql_error() . ')'); }

// Make the list of tables an array
$tablerow = array();
while ($row = mysql_fetch_array($result)) { $tablerow[] = $row; }

// Define variables...
$total_tables = count($tablerow);
$statrow = array();
$total_rows = 0;
$total_rows_average = 0;
$sizeo = 0;

// Get the status of each table
for ($i = 0; $i < count($tablerow); $i++) {
// Query the status...
$sql = "SHOW TABLE STATUS LIKE '{$tablerow[$i][0]}';";
if (!$result = mysql_query($sql)) { die ('Error getting table status (' . $sql . ' :: ' . mysql_error() . ')'); }
// Get the status array of this table
$table_info = mysql_fetch_array($result);
// Add them to the total results
$total_rows += $table_info[3];
$total_rows_average += $table_info[4];
$sizeo += $table_info[5];
}

// Function to calculate size of the file
function c2s($bs) {
if ($bs < 964) { return round($bs) . " Bytes"; }
else if ($bs < 1000000) { return round($bs/1024,2) . " KB" ; }
else { return round($bs/1048576,2) . " MB" ; }
}

// Echo the result!!!!!!!!!
echo "{$total_rows} rows in {$total_tables} tables";
echo "<br>Average size in each row: " . c2s($total_rows_average/$total_tables);
echo "<br>Average size in each table: " . c2s($sizeo/$total_tables);
echo "<br>Database size: " . c2s($sizeo);

// Close the connection
mysql_close();
?>
up
-5
wbphfox at xs4all dot nl
20 years ago
Here is a way to show al the tables and have the function to drop them...

<?php

echo "<p align=\"left\">";
//this is the connection file for the database....
$connectfile = "connect.php";
require
$connectfile;

$dbname = 'DATABASE NAME';

$result = mysql_list_tables($dbname);

echo
"<table width=\"75%\" border=\"0\">";
echo
"<tr bgcolor=\"#993333\"> ";
echo
"<td><font face=\"Verdana, Arial, Helvetica, sans-serif\" size=\"-1\" color=\"#FFFFFF\">Table name:</font></td>";
echo
"<td><font face=\"Verdana, Arial, Helvetica, sans-serif\" size=\"-1\" color=\"#FFFFFF\">Delete?</font></td>";
echo
"</tr>";

if (!
$result) {
print
"DB Error, could not list tables\n";
print
'MySQL Error: ' . mysql_error();
exit;
}

while (
$row = mysql_fetch_row($result)) {
echo
"<tr bgcolor=\"#CCCCCC\">";
echo
"<td>";
print
"$row[0]\n";
echo
"</td>";

echo
"<td>";
echo
"<a href=\"$PHP_SELF?action=delete&table=";
print
"$row[0]\n";
echo
"\">Yes?</a>";

echo
"</td>";

echo
"</tr>";


}

mysql_free_result($result);

//Delete
if($action=="delete")
{
$deleteIt=mysql_query("DROP TABLE $table");
if(
$deleteIt)
{
echo
"The table \"";
echo
"$table\" has been deleted with succes!<br>";
}
else
{
echo
"An error has occured...please try again<br>";
}
}

?>
up
-4
cdarklock at darklock dot com
21 years ago
Actually, the initially posted SELECT COUNT(*) approach is flawless. SELECT COUNT(*) will provide one and only one row in response unless you can't select from the table at all. Even a brand new (empty) table responds with one row to tell you there are 0 records.

While other approaches here are certainly functional, the major problem comes up when you want to do something like check a database to ensure that all the tables you need exist, as I needed to do earlier today. I wrote a function called tables_needed() that would take an array of table names -- $check -- and return either an array of tables that did not exist, or FALSE if they were all there. With mysql_list_tables(), I came up with this in the central block of code (after validating parameters, opening a connection, selecting a database, and doing what most people would call far too much error checking):

if($result=mysql_list_tables($dbase,$conn))
{ // $count is the number of tables in the database
$count=mysql_num_rows($result);
for($x=0;$x<$count;$x++)
{
$tables[$x]=mysql_tablename($result,$x);
}
mysql_free_result($result);
// LOTS more comparisons here
$exist=array_intersect($tables,$check);
$notexist=array_diff($exist,$check);
if(count($notexist)==0)
{
$notexist=FALSE;
}
}

The problem with this approach is that performance degrades with the number of tables in the database. Using the "SELECT COUNT(*)" approach, performance only degrades with the number of tables you *care* about:

// $count is the number of tables you *need*
$count=count($check);
for($x=0;$x<$count;$x++)
{
if(mysql_query("SELECT COUNT(*) FROM ".$check[$x],$conn)==FALSE)
{
$notexist[count($notexist)]=$check[$x];
}
}
if(count($notexist)==0)
{
$notexist=FALSE;
}

While the increase in speed here means virtually nothing to the average user who has a database-driven backend on his personal web site to handle a guestbook and forum that might get a couple hundred hits a week, it means EVERYTHING to the professional who has to handle tens of millions of hits a day... where a single extra millisecond on the query turns into more than a full day of processing time. Developing good habits when they don't matter keeps you from having bad habits when they *do* matter.
up
-4
coffee at hayekheaven dot net
22 years ago
Even though php guy's solution is probably the fastest here's another one just for the heck of it...
I use this function to check whether a table exists. If not it's created.

mysql_connect("server","usr","pwd")
or die("Couldn't connect!");
mysql_select_db("mydb");

$tbl_exists = mysql_query("DESCRIBE sometable");
if (!$tbl_exists) {
mysql_query("CREATE TABLE sometable (id int(4) not null primary key,
somevalue varchar(50) not null)");
}
up
-6
mail at thomas-hoerner dot de
21 years ago
You can also use mysql_fetch_object if you consider a specialty: The name of the object-var is

Tables_in_xxxxx

where xxxxx is the name of the database.

i.e. use

$result = mysql_list_tables($dbname);
$varname="Tables_in_".$dbname;
while ($row = mysql_fetch_object($result)) {
echo $row->$varname;
};
To Top