Field calculation question

[macability]

Hello,

 

Can anybody help me with a SQL query problem which I have. I have 2 fields which I would like to add another 2 more fields with a calculation, one field calculates with a level return, the other is a 10% increase or decrease. For example the table will hold the following data

 

Field_A : Field_B

1 : 1.4

2 : 1.7

1 : 1.3

5 : 1.0

3 : 1.0

 

I would like to only add field A if the result is 1 else I will want to subtract 1 . So I have an SQL statement which looks look like

 

select Field_A, Field_B, SUM(IF(Field_A=1, Field_B.-1)) AS Field_C from mytable group by Field_A ;

 

Field_A : Field_B: Field_C

1 : 1.4 : 1.4

2 : 1.7 : 0.4

1 : 1.3 : 1.7

5 : 1.0 : 0.7

3 : 1.0 : -0.3

 

What I would like to do for the next field (Field_D) is have it count up using a 10% increments for example: If Field_A=1 then I would like take a Field_B and multiply it by a 10% of the bank total. If Field_A does not equal 1 then decrease the bank by 10 %

 

Field_D starts at 1 units

 

Field_A : Field_B: Field_C: Field_D

1 : 1.4 : 1.4 : 1.14

2 : 1.7 : 0.4 : 1.03

1 : 1.3 : 1.7 : 1.16

5 : 1.0 : 0.7 : 1.04

3 : 1.0 : -0.3 : 0.94

 

Any advise people can give me will greatly be appreciated.

 

regards

 

Stevie D.