Insert value through procedure in a table by mysql

Question

I want to insert values into a table by using a procedure. I have 2 tables sales and products; in the product table I have columns id, product_name,product_price, product_quantity and in sales table I have p_id and p_qty.

I want to use a procedure when a user add values in a sales table; this procedure should take 2 arguments for p_id and p_qty.

If p_qty is less than 0 or greater than product_quantity, then showstock is not available

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Answer 1

here is my query

DELIMITER //
CREATE PROCEDURE find_qty_(
    product_id_proc INT,
    product_qty_proc INT
)
BEGIN
    DECLARE
        remaining_stock INT; 
        SELECT product_quantity INTO remaining_stock FROM products
        WHERE id = product_id_proc; 
        IF product_qty_proc>=0 OR product_qty_proc>remaining_stock THEN 
            BEGIN SELECT "stock not available";
            END;
        ELSE 
            INSERT into sales(p_id,p_qty)VALUES(product_id_proc,product_qty_proc);
        END IF; 
    END;;