Hi,

> how can I generate a list of deltas between columns in different rows for 
> the entire table?
> what I need is an sql command that does something like this:
> for N =0 to i do : select "colA of current rowN" - "colA of pervious 
> row(N-1)" from tab1;
> 
> ColA = floating point number.

You can do something like:

select select @v:=0;
select colA-@v,@v:=colA from tab1;

Example:

mysql> select * from ajuda;
+----+----+
| id | a  |
+----+----+
|  1 |  3 |
|  2 |  4 |
|  3 |  5 |
|  4 |  7 |
|  5 | 10 |
+----+----+
5 rows in set (0.00 sec)

mysql> select @v:=0;
+-------+
| @v:=0 |
+-------+
|     0 |
+-------+
1 row in set (0.01 sec)

mysql> select a-@v,@v:=a from ajuda;
+------+-------+
| a-@v | @v:=a |
+------+-------+
|    3 |     3 |
|    1 |     4 |
|    1 |     5 |
|    2 |     7 |
|    3 |    10 |
+------+-------+
5 rows in set (0.00 sec)

mysql> 

-- 
dsoares
(sql)

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