FoxPro How To Correctly Update a Variable Based On Table Values-CodePudding

I am writing a FoxPro program which is accessing multiple tables and updating some of their values after running values through equations. I am trying to store the result of an equation in a variable (set) as such:

b = table1.base
ser = table2.load*b

Despite not showing some of the surrounding code, this should return a positive numeric value, however it just returns 0.0. What I have noticed is that if I print this quantity,

?table2.load*b

it indeed prints the correct result. How come this correct result is not being stored in the variable ser ? Thanks for any help.

CodePudding user response：

First, I wouldn't use "set" as a variable name because it's a reserved word.

How are you checking the value of the result? Try looking with the Debugger. It should be in the Locals window.

Tamar

CodePudding user response：

The following code would reproduce your observation, and the solution to cure the spooky symptom would be FoxPro's peculiar m. prefix which clarifies that a certain name expression is a variable as opposed to an (alias.)column. Don't hesitate to post back if your scenario / reason / repro is somehow different

CLEAR 
CREATE CURSOR table1 (base Int)
INSERT INTO table1 VALUES (15)
CREATE CURSOR table2 (load Int)
INSERT INTO table2 VALUES (6)

LOCAL b, ser
b = table1.base

CREATE CURSOR SomethingElse(b Int Null)
INSERT INTO somethingElse VALUES (0)
ser = table2.load * b
? ser && prints 0

ser = table2.load * m.b && the m. tells FoxPro that b is a variable as opposed to an alias row/column

? m.ser && prints 90