ClickHouseFixedStringToStringPropertyHandler

A property handler that maps the ClickHouse FixedString(N) type into a string property without the trailing NUL padding.

A property handler that maps the ClickHouse FixedString(N) type into a string property. ClickHouse pads a shorter value with trailing NUL (\0) characters up to N bytes; this handler removes that padding when reading, so the property holds the original text.

Overview

Conversions

Exceptions

Usability

Bind the handler to the property that maps to a FixedString(N) column.

Attribute

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

    [Map("code"), PropertyHandler(typeof(ClickHouseFixedStringToStringPropertyHandler))]
    public string Code { get; set; }
}

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

using (var connection = new ClickHouseConnection(connectionString))
{
    connection.Insert(new Country { Id = 1, Code = "NO" });
    var country = connection.Query<Country>(e => e.Id == 1).First();
    // country.Code is "NO", without the padding of a FixedString(3) column
}

Fluent Mapping

To configure via FluentMapper:

FluentMapper
    .Entity<Country>()
    .PropertyHandler<ClickHouseFixedStringToStringPropertyHandler>(e => e.Code);

Property Level Mapping

To configure via PropertyHandlerMapper:

PropertyHandlerMapper.Add<Country, ClickHouseFixedStringToStringPropertyHandler>(e => e.Code, new ClickHouseFixedStringToStringPropertyHandler(), true);

Type Level Mapping

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

PropertyHandlerMapper.Add<string, ClickHouseFixedStringToStringPropertyHandler>(new ClickHouseFixedStringToStringPropertyHandler(), 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 FixedString(N) column.