Subject | Re: Double precision field problem |
---|---|

Author | Adam |

Post date | 2006-10-30T22:32:15Z |

--- In firebird-support@yahoogroups.com, "ibrahim bulut" <i.bulut@...>

wrote:

This behaviour is perfectly normal for the datatype you are using. The

problem is you are expecting numeric behaviour.

Read the following article:

http://en.wikipedia.org/wiki/Floating_point

Particularly point 9 (4 is also useful).

Adam

wrote:

>Double Precision is a floating point style number type, not a numeric.

>

>

> i am in trouble double precision field with subtract operation

>

>

>

> field1 is double precision

>

> field2 is double precision

>

>

>

> field1's value is 79.69

>

> field2's value is 78.12

>

>

>

> when i subtract field2 from field1 with this sql statement

>

> select field1 - field2 from table1

>

> the result is 1,56999999999999

>

>

>

> the result must be 1,57

>

>

>

> what is the problem

This behaviour is perfectly normal for the datatype you are using. The

problem is you are expecting numeric behaviour.

Read the following article:

http://en.wikipedia.org/wiki/Floating_point

Particularly point 9 (4 is also useful).

Adam