>How can i create an index for two numeric fields thats result is same with this;
>
>select * from table1 order by a,b
>
>a and b are numeric fields.
If a and b are non-negative:
INDEX ON STR(A,
size,
decimal precision) + STR(B,
size,
decimal precision) ...
will work to build a string expression by concatenation. Another approach where the issue of total decimal precision of the two concatented expressions will fit within the limits of precision of a VFP floating point computation:
INDEX ON (a * 10^
order of magnitude of max value of B+1)+ b +...
will result in a number adjusted for relative magnitude; the first has the advantage of being magnitude/precision independent at the cost of not working correctly when negative values are possibly an issue. With very large numbers, rounding inherent in floating point representations can step in and make things mis-sort since the decimal precision of a computation has limits as we've discuissed before.
>Thanks
