I'm trying to know is some table is empty or no, now I am realized this issue with this code:
// if table is empty it must return TRUE, if full FALSE
private function isEmpty($tableName)
{
if ($result = $this->mysqli->prepare("SELECT COUNT(*) FROM ?"))
{
$result->bind_param("s",$tableName);
$result->execute();
$row_cnt = $result->num_rows;
if (empty($row_cnt))
{
return TRUE;
}
else
{
return FALSE;
}
}
}
this code seems not a really perfect, I would like to know is there a better way to get the same results, but using predicat SQL EXISTS or something else? Thank you.
updated: thanks for comments and answer, but anyway I dont have a clue how to do it, it's calls an error:
$mysqli = new mysqli("localhost","root","","database");
if ($result = $mysqli->prepare("SELECT COUNT(*) FROM `talbe` LIMIT 1"))
{
$row = $result->fetch_row();
echo "<pre>";
print_r($row);
echo "</pre>";
$result->close();
}
$mysqli->close();
[Sat Jun 09 11:25:34 2012] [error] [client 127.0.0.1] PHP Fatal error: Call to undefined method mysqli_stmt::fetch_row() in F:\server\sites\home\test.loc\www\empty.php on line 9
updated:
$mysqli = new mysqli("localhost","root","","db");
if ($result = $mysqli->query("SELECT * FROM `table` LIMIT 1"))
{
if ($obj = $result->fetch_object())
{
echo "NOT EMPTY";
}
else
{
echo "empty";
}
$result->close();
}
$mysqli->close();
this is it.
COUNT(*) is fine for determining if a table is empty, providing the table doesn't have huge number of rows.
Another alternative would be SELECT (something) FROM ${table} LIMIT 1; if that returns a result then the table isn't empty.
But are you sure it's possible to set table name via a parameter like that in mysqli? I didn't think it was, need to check.