validate MySQL select query processed successfully

What i'm trying is validate a select query is processed successfully. With DB transaction we can validate INSERT , UPDATE, DELETE

like shown below in Codeigniter

$this->db->trans_begin();
//query
if($this->db->trans_status() == false){                 
     return ['error' => 1, 'message' => 'Error massage'];          
}

but it does not work with SELECT query. Is there any other ways to validate this.

Actually my select query will be like this in a scenario

SELECT (amount1+ 10 / 100) FROM test_table

the formula (amount1+ 10 / 100) in the above query will be decoded from the user input. some time a wrong input from user can be like this.

(amount1+ + 10 / 100)

so at the time select query will not execute.

@sintakonte the user input that i mentioned is a formula from a formula builder. so finally i did a simple trick to validate the query (formula). do an insertion or update to the table with the select query. In my scenario once i get the result from the select query i have to update a column in a table.

$this->db->trans_begin();
$this->db->query("UPDATE table2 
                  JOIN ( 
                      SELECT (amount1+ 10 / 100) AS amnt, empID FROM test_table
                  ) AS calculationTB
                  ON calculationTB.empID = table2.empID AND 
                  SET fnTB.ssoEmployer=calculationTB.amnt");

if($this->db->trans_status() == false){                 
   return ['error' => 1, 'message' => 'Error massage'];          
}

$this->db->trans_commit();