mysqli - How to search a word on two table if have or not by php query -

i want find out userid 2 table username username have stayed in table2 or not. means if username match in table query collect userid.

table 1:  username --- userid  > john --- 100  table 2:  username --- userid  > colin --- 101 

i read many article here nut cannot understand should do.

now think: need john's uesrid,

so tried:

$username = "john";  $q = "select userid table1,table2 table1.username = '$username' or table2.username = '$username'"; $result = mysqli_query($this->connection, $q); 

from understand want check if name exist in 1 of tables.

here easy php code:

<?php  session_start();   include 'db_connect.php';   $check_1 = mysqli_query("select * table_1 username = '$username'");  $check_2 = mysqli_query("select * table_2 username = '$username'");   if(mysqli_num_rows($check_1)==0){      //didnt exist in table 1   }   else if(mysqli_num_rows($check_2)==0){      //no result in table 2 either.  }  else{      //what want if username doesnt exist  } 

let me know how worked out :)