Question

I’m searching for a way to compare two tables, and determine which rows are missing in one table. These two tables are on different MySQL servers.

Table 1
----------------
Apple
Microsoft
Google

Table 2 
----------
Apple
Google

What I want is to show a list of the items from Table 1 that are missing.

Answer 1

There are a few ways to get the outcome you want, if you want to use PHP it is easiest like so:

$table1 = mysql_query("SELECT fieldname.....");
$table2 = mysql_query("SELECT fieldname.....");

$results_table2 = mysql_fetch_array($table2);
while($row = mysql_fetch_assoc($table2))
  {

  if(!in_array($row['fieldname'], $results_table2))
    {

    echo $row['fieldname'] ." not in both tables";

  }

}

Maybe even work with array_intersect instead of a while loop.

$table1 = mysql_query("SELECT fieldname.....");
$table2 = mysql_query("SELECT fieldname.....");

$results_table1 = mysql_fetch_array($table1, MYSQL_ASSOC);
$results_table2 = mysql_fetch_array($table2, MYSQL_ASSOC);

$result1 = array_intersect($results_table1, $results_table2);
print_r($result1);

$result2 = array_diff($results_table1, $results_table2);
print_r($result2);