Handlers · 2 min read

FirebirdDecFloatToNullableDecimalPropertyHandler

A property handler that maps the Firebird DECFLOAT types into a nullable decimal property, rejecting values that do not fit.

A property handler that maps the Firebird DECFLOAT(16) and DECFLOAT(34) types into a Nullable<decimal> property.

A decimal cannot hold every DECFLOAT value (34 digits, wide exponent, NaN and infinity), so such values are rejected instead of being silently altered. Use FirebirdDecFloatToStringPropertyHandler to keep them.

Overview

Name	Description
Class	`FirebirdDecFloatToNullableDecimalPropertyHandler`
Namespace	`RepoDb.PropertyHandlers.Firebird`
Package	RepoDb.Firebird
Implements	IPropertyHandler`<object, decimal?>`
Column type	The Firebird `DECFLOAT(16)` and `DECFLOAT(34)` types
Property type	`decimal?`

Conversions

Method	Direction	Description
Get	Database to property	Converts the value returned by the driver (an `FbDecFloat`, a `decimal`, or a `string`) into a `decimal?`. `null` and `DBNull` are returned as `null`.
Set	Property to database	Converts the `decimal` into an `FbDecFloat`, keeping its coefficient and scale, to be written into the `DECFLOAT` column. A `null` value is written as `null`.

Exceptions

Exception	Thrown When
`OverflowException`	The value is outside of the range of a `decimal`.
`FormatException`	The value is `NaN` or infinity.
`ArgumentException`	The type of the value returned by the driver is not supported.

Usability

Bind the handler to the property that maps to a nullable DECFLOAT column.

Attribute

public class Quote
{
    public int Id { get; set; }

    [Map("discount"), PropertyHandler(typeof(FirebirdDecFloatToNullableDecimalPropertyHandler))]
    public decimal? Discount { get; set; }
}

Once bound, the library invokes the handler automatically when the property is read or written.

using (var connection = new FbConnection(connectionString))
{
    connection.Insert(new Quote { Id = 1, Discount = null });
    var quote = connection.Query<Quote>(e => e.Id == 1).First();
    // quote.Discount is null
}

Fluent Mapping

To configure via FluentMapper:

FluentMapper
    .Entity<Quote>()
    .PropertyHandler<FirebirdDecFloatToNullableDecimalPropertyHandler>(e => e.Discount);

Property Level Mapping

To configure via PropertyHandlerMapper:

PropertyHandlerMapper.Add<Quote, FirebirdDecFloatToNullableDecimalPropertyHandler>(e => e.Discount, new FirebirdDecFloatToNullableDecimalPropertyHandler(), true);

Type Level Mapping

To apply the handler to every property of the type decimal?:

PropertyHandlerMapper.Add<decimal?, FirebirdDecFloatToNullableDecimalPropertyHandler>(new FirebirdDecFloatToNullableDecimalPropertyHandler(), true);

A type level mapping is process-wide: it is applied to every decimal? property of every entity and connection, not only to the intended column. Prefer the attribute, fluent or property level mapping unless every decimal? property maps to a DECFLOAT column.