PHP无法打印mysql_query（）结果

Question

I have code

$email = "jb@tlb.com";    
$row = mysql_query("SELECT EXISTS(SELECT email FROM accounts WHERE email='".$email."');");
echo $row[0];

However, nothing is echoed.

This is strange because something is being returned because, later in the code I have a function that is CALLED:

if ( $row[0] == 0 ) { echo "Email address is available<br>";};

However: this is strange because when i put the SAME CODE into mySQL database command prompt:

It clearly returns 1 or TRUE.

The mysql_query is returning 0 when the same exact command in mysql command prompt returns 1. Further: I am unable to echo the result for debugging purposes.

EDIT: Please not, the regular mySQL command is returning this and ONLY this:

EDIT: Here is there entire database:

Answer 1

MySQL query gives you a ressource. After that you have to fetch the data with mysql_fetch_assoc or mysql_fetch_row or something else for example. But its better to use prepared statements with mysqli or PDO to get more security.

$email = "jb@tlb.com";    
$res = mysql_query("SELECT EXISTS(SELECT email FROM accounts WHERE email='".myql_real_escape_string($email)."')");
$row = mysql_fetch_assoc($res);
echo $row['email'];

Answer to your question:

$email = "jb@tlb.com";    
$res = mysql_query("SELECT email FROM accounts WHERE email='".mysql_real_escape_string($email)."')");
$numRows = mysql_num_rows($res);

if($rowRows > 0) {
    echo "Record Available";
}

Answer 2

You need to actually retrieve the result set from the query. mysql_query() just returns a resource handle for a successful select. You then need to fetch the results using mysql_fetch_* class of functions. Alternatively, you can use mysql_num_rows() to determine the number of rows returned in the result set.

In this case it is really senseless to wrap your actual query into a subquery. Just run your select and determine the number of rows:

$email = "jb@tlb.com";    
$result = mysql_query("SELECT email FROM accounts WHERE email='".$email . "'");
if($result) {
    $row_count = mysql_num_rows($result);
    echo $row_count;
}

Also, you should not be writing new code using mysql_* functions, as these are deprecated. I would suggest mysqli or PDO extensions instead.

Answer 3

You need to do something like

while ($r = mysql_fetch_assoc($row)) 
{ 
    echo $r[0];                                 
}

after that code.

Let me know.