How can I check if a MySQL table exists with PHP?

Question

As simple in theory as it sounds I\'ve done a fair amount of research and am having trouble figuring this out.

How can I check if a MySQL table exists and if it does

Answer 1

125 microsecond table exists check

.000125 sec. (125µs)

mysql_unbuffered_query("SET profiling = 1");  // for profiling only

@mysql_unbuffered_query("SELECT 1 FROM `table` LIMIT 1 ");
if (mysql_errno() == 1146){

 // NO EXISTING TABLE CODE GOES HERE

}
elseif(mysql_errno() > 0){

  echo mysql_error();    

}

$results = mysql_query("SHOW PROFILE");  // for profiling only

Execution time, measured using mysql profiling, when a table exists, or not, is about .000125 sec. (125µs)

The LIMIT 1 is important for speed. This minimizes the Sorting Result and Sending Data query State times. And table size is not a factor.

I always use an unbuffered query when no results are required.

PROFILE RESULTS WHEN TABLE DOES NOT EXIST

QUERY STATE           SECONDS   
--------------------  -------
starting              0.000025  
checking permissions  0.000006  
Opening tables        0.000065  
query end             0.000005  
closing tables        0.000003  
freeing items         0.000013  
logging slow query    0.000003  
cleaning up           0.000003  
TOTAL                 0.000123  <<<<<<<<<<<< 123 microseconds

WHEN TABLE EXISTS

QUERY STATE           SECONDS   
--------------------  -------
starting              0.000024
checking permissions  0.000005
Opening tables        0.000013
System lock           0.000007
init                  0.000006
optimizing            0.000003
statistics            0.000009
preparing             0.000008
executing             0.000003
Sending data          0.000019
end                   0.000004
query end             0.000004
closing tables        0.000006
freeing items         0.00001
logging slow query    0.000003
cleaning up           0.000003
TOTAL                 0.000127 <<<<<<<<<<<< 127 microseconds

Answer 2

It was already posted but here it is with PDO (same query)...

$connection = new PDO ( "mysql:host=host_db; dbname=name_db", user_db, pass_db );

if ($connection->query ("DESCRIBE table_name"  )) {
    echo "exist";
} else {
    echo "doesn't exist";
}

Works like a charm for me....

And here's another approach (i think it is slower)...

if ($connection->query ( "SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE table_schema = 'db_name' AND table_name ='tbl_name'" )->fetch ()) {
    echo "exist";
} else {
    echo "doesn't exist";
}

You can also play with this query:

SHOW TABLE STATUS FROM db_name LIKE 'tbl_name'

I think this was suggested to use in the mysql page.

Answer 3

The cleanest way to achieve this in PHP is to simply use DESCRIBE statement.

if ( mysql_query( "DESCRIBE `my_table`" ) ) {
    // my_table exists
}

I'm not sure why others are posting complicated queries for a such a straight forward problem.

Update

Using PDO

// assuming you have already setup $pdo
$sh = $pdo->prepare( "DESCRIBE `my_table`");
if ( $sh->execute() ) {
    // my_table exists
} else {
    // my_table does not exist    
}

Answer 4

mysql_query("SHOW TABLES FROM yourDB");
//> loop thru results and see if it exists
//> in this way with only one query one can check easly more table 

or mysql_query("SHOW TABLES LIKE 'tblname'");

Don't use mysql_list_tables(); because it's deprecated

Answer 5

$res = mysql_query("SELECT table_name FROM information_schema.tables WHERE table_schema = '$databasename' AND table_name = '$tablename';");

If no records are returned then it doesn't exist.

Answer 6

Or you could use

show tables where Tables_in_{insert_db_name}='tablename';