Duplicate record in postgresql from CodeIgniter

Hi Everyone,

 Before I have used mysql, for insert action my code : 

// in mymodel
 public function insertData($table, $data) {
        $res=$this->db->insert($table, $data);
        return  $db_error = $this->db->error();
         
    }
// in my controller 
 $result = $this->mymodel->insertData($mytable, $data);


if ($result['code'] == 1062){
echo "dublicate"
}

However now I am using postgresql and it returns error like this:

A PHP Error was encountered
Severity: Warning
Message: pg_query(): Query failed: ERROR: duplicate key value violates unique constraint "user_keywords_keyword_key" DETAIL: Key (keyword)=(fa) already exists.
Filename: postgre/postgre_driver.php
Line Number: 242

array(2) { ["code"]=> string(0) "" ["message"]=> string(126) "ERROR: duplicate key value violates unique constraint "user_keywords_keyword_key" DETAIL: Key (keyword)=(fa) already exists." } 


my question is that how to ignore this error