防止在MySql中插入匹配的行

Question

I have a table in MySql Database. I would like to prevent inserting matching rows in MySql. Like I have 4 columns in a table. I would not like to insert any row which has matching values of these 4 columns. I am trying to show that below

My table
----------
 product_name| product_sku |product_quantity| product_price
----------
 Computer    | comp_007    | 5              | 500

I would like to prevent to insert same row again. How can I do that using MySql Query ??

UPDATE

I would not like to insert again

---

 Computer    | comp_007    | 5              | 500

But I would like to insert below rows

---

 mouse       | comp_007    | 5               | 500

---

 Computer    | comp_008    | 5               | 500

---

 Computer    | comp_007    | 50              | 500

---

 Computer    | comp_007    | 5               | 100

---

 mouse       | mou_007     | 5               | 500

Answer 1

Create a combined unique key / composite key on the columns in question:

ALTER TABLE `table` ADD UNIQUE (
`product_name` ,
`product_sku` ,
`product_quantity`,
`product_price`
);

Any attempts to insert duplicate rows will result in a MySQL error.