How to check a database table for the existence of a record?

Question

opencart

In the module I enter the name of the skin in the input field and after that I load the database file for import

I write the name of the new skin to the database

move_uploaded_file($this->request->files['import']['tmp_name'], $filename);
            $skin_name = $this->request->post['skin_name'];
            $this->db->query("INSERT INTO  `oc_testtheme_skin` (`skin_name`) VALUES ('$skin_name');");

If you enter the same name 2 times, it will write exactly the same name.

As possible before

move_uploaded_file($this->request->files['import']['tmp_name'], $filename);

check if such a skin name exists in the table, and if so, display a warning that this name already exists ?

Here is a check before move_uploaded_file gives alert "error"

$query = $this->db->query("SELECT oc_testtheme_skin FROM skin_name");
            $existedSkinname = $query->rows;
            if (in_array($this->request->post['skin_name'], $existedSkinname)) {
                echo "exists";
            }

Answer 1

spoiler

SELECT что FROM таблица

SELECT skin_name FROM oc_testtheme_skin

Answer 2

as an option, make the field UNIQUE and do the insert
INSERT IGNORE
or
INSERT ..... ON DUPLICATE KEY UPDATE