MySQL temporary column with calculated field

Question

I have a MySQL table:

Now i want to make a small calculate in the query. I want that there is a temporary column where you see the (product_price + 4).

So when there is a product with the price of 16 (product_price). Then there should be a tempory column eg product_newprice = 20

Answer 1

SELECT product_id,product_name,product_price,(product_price +4) product_newprice  FROM table

Answer 2

Query would look like this:

SELECT p.product_id
     , p.product_name
     , p.product_price
     , p.product_price + 4.00 AS product_newprice
  FROM mytable p

Answer 3

select product_id, product_name, product_price, product_price + 4 as product_price2 from YourTable.

Answer 4

Others have shown how to do an individual SELECT statement to calculate the adjusted value, but this means you have to code this in every query you want to return that value.

If you want to make the column part of the table definition so any query will get the adjusted value, you have these options:

• Create a VIEW that includes the new column of product_price+4 , and only query the VIEW.

• Add another real column for the adjusted price, and keep it updated with triggers that calculate the new value on INSERT and UPDATE.

• Use MariaDB, a fork of MySQL, which supports virtual columns , which may be calculated on the fly as expressions against other columns.