# CREATE TABLE
CREATE TABLE accounts (
    id INT GENERATED BY DEFAULT AS IDENTITY,
    name VARCHAR(100) NOT NULL,
    balance DEC(15,2) NOT NULL,
    PRIMARY KEY(id)
);

# INSERT
INSERT INTO accounts(name,balance) VALUES
('Bob',10000), ('Alice',10000);

# STORED PROCEDURE
CREATE OR REPLACE PROCEDURE transfer(INT, INT, DEC)
LANGUAGE plpgsql
AS $$
BEGIN
    -- subtracting the amount from the sender's account
    UPDATE accounts
    SET balance = balance - $3
    WHERE id = $1;

    -- adding the amount to the receiver's account
    UPDATE accounts
    SET balance = balance + $3
    WHERE id = $2;

    COMMIT;
END;
$$;

# Controller
class Account extends CI_Controller {
    public function index() {
        $stored_procedure = 'CALL transfer(?, ?, ?)';
        $parameter = [1, 2, 1000];

        $result = $this->db->query($stored_procedure, $parameter);
    }
}