Hello all,
Could anyone comment on User Variable behavior in the example below?
Thanks,
Vadim.
============================================================================
=
mysql> SELECT
-> LEFT(CallTime,10) AS CallDate,
-> @a := SUM(Charge),
-> @b := SUM(Cost),
-> @a - @b,
-> @a,
-> @b
-> FROM Calls
-> GROUP by CallDate
-> ORDER BY CallDate DESC;
+------------+-------------------+-----------------+---------+--------+-----
-+
| CallDate | @a := SUM(Charge) | @b := SUM(Cost) | @a - @b | @a | @b
|
+------------+-------------------+-----------------+---------+--------+-----
-+
.
| 2004-03-01 | 621.059 | 249.310 | 30.882 | 39.512 | 8.63
|
| 2004-02-29 | 54.620 | 17.660 | 30.882 | 39.512 | 8.63
|
| 2004-02-28 | 205.581 | 17.460 | 30.882 | 39.512 | 8.63
|
| 2004-02-27 | 622.282 | 248.920 | 30.882 | 39.512 | 8.63
|
| 2004-02-26 | 607.274 | 277.100 | 30.882 | 39.512 | 8.63
|
| 2004-02-25 | 709.698 | 308.580 | 30.882 | 39.512 | 8.63
|
| 2004-02-24 | 783.210 | 298.560 | 30.882 | 39.512 | 8.63
|
| 2004-02-23 | 799.764 | 252.890 | 30.882 | 39.512 | 8.63
|
.
