How would I...

kaos057

I want to make a new field in my table that divides one field by the other to get its value. Not sure if there is a way to do it with php oy mysql. I know I can do it when the info is entered but all the info is allready entered. Anyone help me with this?

matt_4013

Hi there.

When you create your query, do it like this:

SELECT field1, field2, (field1 / field2) AS divided_fields FROM table

Just to clarify this, in queries you don't have to only select the fields you've already got. You can create new ones, you can create temporary fields that will only be in the results of that particular query, you can really do whatever the hell you like with them.

drawmack

If your database is storing information that you can calculate then it is a very poor database design.

matt_4013

Why is this poor database design?

drawmack

If field c = field a/fieldb and you store field c instead of calculating field c you have created two problems

1) database size - by storing that information you have just made your database larger then it needs to be

2) your programming gets bloated because everytime field a or field b changes you have to update field c which can lead to database corruption.

matt_4013

Did you read what the query was doing?

It IS calculating it.

drawmack

Originally posted by matt_4013
Did you read what the query was doing?

It IS calculating it.

did you notice that I wasn't quoting you which ment I was probably responding to the original poster.