Subject | Re: [firebird-support] Double precision field problem |
---|---|

Author | Svein Erling Tysvaer |

Post date | 2006-10-30T12:50:44Z |

You get what you ask for, Ibrahim. Floating point numbers (e.g. double

precision) are good for measuring things, it doesn't matter whether the

length of a line is 1.57 metres or 1.5699999999999 metres. Field1

doesn't have the exact value 79.69, it has a value of approximately

79.69 (e.g. 79.69000000000000001238) and similar for Field2.

If such differences do matter, you should probably use fixed point

numbers - e.g. decimal or numeric.

HTH,

Set

ibrahim bulut wrote:

precision) are good for measuring things, it doesn't matter whether the

length of a line is 1.57 metres or 1.5699999999999 metres. Field1

doesn't have the exact value 79.69, it has a value of approximately

79.69 (e.g. 79.69000000000000001238) and similar for Field2.

If such differences do matter, you should probably use fixed point

numbers - e.g. decimal or numeric.

HTH,

Set

ibrahim bulut wrote:

>

> 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

>

> ibrahim bulut

> software and database expert

> iletisim online ltd.sti.

> turkish republic