Handlers · 2 min read

Db2DecimalFloatToStringPropertyHandler

A property handler that maps the Db2 DECFLOAT type into a string property that keeps the full precision and the special values.

A property handler that maps the Db2 DECFLOAT type into a string property, which keeps the full precision (up to 34 digits) and the special values (NaN and infinity) of the IEEE 754 decimal floating-point value.

Overview

Name	Description
Class	`Db2DecimalFloatToStringPropertyHandler`
Namespace	`RepoDb.PropertyHandlers.Db2`
Package	RepoDb.Db2
Implements	IPropertyHandler`<object, string>`
Column type	The Db2 `DECFLOAT` type
Property type	`string`

Conversions

Method	Direction	Description
Get	Database to property	Converts the value returned by the driver into its text form. A `DB2DecimalFloat.Null`, `null` and `DBNull` value is returned as `null`.
Set	Property to database	Converts the text form of a `DECFLOAT` value into a `DB2DecimalFloat`, to be written into the column. A `null` or an empty string is written as `null`.

Exceptions

Exception	Thrown When
`ArgumentException`	The type of the value returned by the driver is not supported.

Usability

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

Attribute

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

    [Map("reading"), PropertyHandler(typeof(Db2DecimalFloatToStringPropertyHandler))]
    public string Reading { get; set; }
}

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

using (var connection = new DB2Connection(connectionString))
{
    connection.Insert(new Measurement { Id = 1, Reading = "1234567890.123456789" });
    var measurement = connection.Query<Measurement>(e => e.Id == 1).First();
    // measurement.Reading keeps the full precision as text
}

Fluent Mapping

To configure via FluentMapper:

FluentMapper
    .Entity<Measurement>()
    .PropertyHandler<Db2DecimalFloatToStringPropertyHandler>(e => e.Reading);

Property Level Mapping

To configure via PropertyHandlerMapper:

PropertyHandlerMapper.Add<Measurement, Db2DecimalFloatToStringPropertyHandler>(e => e.Reading, new Db2DecimalFloatToStringPropertyHandler(), true);

Type Level Mapping

To apply the handler to every property of the type string:

PropertyHandlerMapper.Add<string, Db2DecimalFloatToStringPropertyHandler>(new Db2DecimalFloatToStringPropertyHandler(), true);

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