MySQL 函数
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mysql_list_tables

(PHP 4, PHP 5)

mysql_list_tables — 列出 MySQL 数据库中的表

说明

resource mysql_list_tables ( string $database [, resource $link_identifier ] )

mysql_list_tables() 接受一个数据库名并返回和 mysql_query() 函数很相似的一个结果指针。用 mysql_tablename() 函数来遍历此结果指针，或者任何使用结果表的函数，例如 mysql_fetch_array()。

database 参数是需要被取得其中的的表名的数据库名。如果失败 mysql_list_tables() 返回 FALSE。

为向下兼容仍然可以使用本函数的别名 mysql_listtables()，但反对这样做。

Note: 该函数已经被删除了，请不要再使用该函数。您可以用命令 SHOW TABLES FROM DATABASE 来实现该函数的功能。

Example #1 mysql_list_tables() 例子

<?php
    $dbname = 'mysql_dbname';

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

    $result = mysql_list_tables($dbname);

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

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

    mysql_free_result($result);
?>

参见 mysql_list_dbs() 和 mysql_tablename()。

MySQL 函数
在线手册：中文 英文
PHP手册
PHP手册 - N: 列出 MySQL 数据库中的表

用户评论:

jdhockad at hotmail dot com (08-Mar-2012 08:07)

Having tried all the suggestions above I had no joy (with attempting to sniff for the existence of an empty table).

The method I found to work is:

$sql = "select count(*) from " . STATUS_TABLE . ";";
                $table = true;
                $rs = @mysqli_query($db, $sql) or $table = false;
                if ($table) {

                        [...]

                }

daniel at eguest dot net (24-Jul-2008 10:13)

Just a simple note:

mysql-list-tables change the context of your active database.

for example:
<?php
//set databse context to db1
mysql_select_db("db1");

//list database tables from db2
mysql-list-tables("db2");
?>

-> Now your active database is db2 and not db1. You have to consider using your sql statements.

kroczu at interia dot pl (08-Dec-2006 11:01)

<?
// 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."'")))
{
 //...
}

?>

mrkvomail at centrum dot cz (29-Jan-2006 07:48)

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));
}

Anonymous (15-Dec-2005 02:38)

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();
?>

sindijs at apollo dot lv (06-Sep-2005 01:21)

Get next auto_increment value:
<?
 
  mysql_connect("localhost", "login", "passwd") or
         die("Cannot connect: " . mysql_error());
   
    mysql_select_db("db_name");
 
  $res = mysql_query("SHOW TABLE STATUS LIKE 'table_name' ") or die(mysql_error());
 
  $row_res = mysql_fetch_array($res);
  echo $row_res[Auto_increment];
 ?>

daveheslop (dave heslop) (08-May-2005 12:45)

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.

wbphfox at xs4all dot nl (09-Sep-2003 05:55)

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>";
}
}
 
?>

thebitman at attbi dot com (07-May-2003 09:49)

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!

daevid at daevid dot com (17-Dec-2002 12:36)

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";
}

cdarklock at darklock dot com (06-Dec-2002 04:03)

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.

(30-Oct-2002 01:42)

<?
/*
   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; }
?>

mail at thomas-hoerner dot de (04-Oct-2002 05:24)

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;
};

NewToPHP_Guy at Victoria dot NOSPAM dot com (02-Oct-2002 10:06)

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));

coffee at hayekheaven dot net (18-Jun-2002 01:48)

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)");
}