autosetting a field in a mysql based on the value of another 2 fields in the same table

[ajoo]

Hi all !, 

 

I was just wondering if it's possible to autoset the value of a field in mysql table based on the value of another 2 fields values.

 

for example if I wish to implement AND logic  on some fields :

 

F1        F2                  F1_F2

========================

0           0                        0

1           0                        0

0           1                        0

1           1                        1

=====================

 

If I have columns F1, F2 &  F1_F2, can the mysql database auto set the value of the F1_F2 based on the values of F1 and F2 as in the table above. If so kindly show how it can be done. Please note that the values of F1 and F2 will be set programmatically using PHP.

 

Thank You.

 

[Jacques1]

Why do you need a physical column for the AND operation when the value can simply be derived ad hoc? Precalculating the result is actually a bad idea, because you need to update it whenever any of F1 or F2 change. And if you forget to update it just once, you'll end up with garbage data.

 

Simple calculate the AND result in the query. You could also use a view which contains a virtual F1_F2 column that is calculated from the physical F1 and F2 columns.

[ajoo]

Hi Guru Jacques, 

 

hmmm ofcourse you are right !