覆盖长文本字符串的流畅 NHibernate nvarchar(MAX) 而不是 nvarchar(255) [英] Override for fluent NHibernate for long text strings nvarchar(MAX) not nvarchar(255)

问题描述

当您在 fluent NHibernate 中设置字符串值时，它总是将 DB 值设置为 Nvarchar(255)，我需要存储相当多的基于用户输入的长字符串，而 255 是不切实际的.

补充一点，这是自动映射器的一个问题，因为我正在使用流畅的 NHibernate 来构建数据库.

解决方案

添加此约定会将字符串属性的默认长度设置为 10000.正如其他人所指出的，这将是一个 nvarchar(max) 列.

public class StringColumnLengthConvention : IPropertyConvention, IPropertyConventionAcceptance{public void Accept(IAcceptanceCriteriacriteria){标准.期望(x => x.Type == typeof(string)).Expect(x => x.Length == 0);}公共无效应用(IPropertyInstance 实例){实例长度(10000)；}}

可以像这样将约定添加到自动映射配置中:

Fluently.Configure().Mappings(m =>m.AutoMappings.Add( AutoMap.AssemblyOf().Conventions.Add()))

有关详细信息，请参阅 Fluent NHibernate wiki 中的约定.>

When ever you set a string value in fluent NHibernate it alwasy sets the DB vales to Nvarchar(255), I need to store quite a lot of long string which are based on user inputs and 255 is impractical.

Just to add this is an issue with the automapper as I am using fluent NHibernate to build the database.

解决方案

Adding this convention will set the default length for string properties to 10000. As others have noted, this will be a nvarchar(max) column.

public class StringColumnLengthConvention : IPropertyConvention, IPropertyConventionAcceptance
{
    public void Accept(IAcceptanceCriteria<IPropertyInspector> criteria)
    {
        criteria.Expect(x => x.Type == typeof(string)).Expect(x => x.Length == 0);
    }
    public void Apply(IPropertyInstance instance)
    {
        instance.Length(10000);
    }
}

Conventions can be added to an automap configuration like this:

Fluently.Configure()
    .Mappings( m =>
        m.AutoMappings.Add( AutoMap.AssemblyOf<Foo>()
        .Conventions.Add<StringColumnLengthConvention >()))

For more information, see Conventions in the Fluent NHibernate wiki.

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