one union select or two selects

[searain]

For example

I have two tables.

tabel1: category has two fields

categorycode, categoryname

table2: products has fields

categorycode, productcode, productname, productprice etc.

i want to display all the products with all its fields values (but replacethe categorycode with categoryname)

approach 1

select product.*, category.name from product, category where categorycode.categorycode=product.categorycode

appoaceh 2

select * from product

also

select * from category

and get the array to transfer categorycode to categoryname categoryname[categorycode]="categoryname"

then display the results from "select * from product"

but use the categoryname[categorycode] instead of categorycode in the display.

which one is better?

the approach 1 is the standard approach i think. but the approach 2 i may be able to reuse in some cases.

[tomhath]

Use Approach 1.

That's the whole point of using a relational database instead of simple files. In fact, that's what the word "relation" means; you are relating the data in one table to data in another.

And what reuse do you expect to get? Approach 2 is just a rudimentary join of two tables by one column. There's nothing to reuse, SQL can already do joins.