ServiceStack.OrmLite:StringLengthAttribute.MaxText 生成“LONGTEXT"；- 如何设置为“文本"? [英] ServiceStack.OrmLite: StringLengthAttribute.MaxText produces "LONGTEXT" - how can I set to "TEXT"?

问题描述

使用 ServiceStack 的 OrmLite 并使用以下属性装饰属性，创建一个 LONGTEXT 类型的列，而不是文档中所述的 o TEXT:

Using ServiceStack's OrmLite and decorating a Property with the following attribute, creates a column of type LONGTEXT, instead o TEXT as noted in the docs:

但它变成了 LONGTEXT:

But it becomes LONGTEXT:

我尝试将 StringLenghtAttribute 设置为其他内容，65535、70000、Int32.MaxValue 等，但是它要么将其解释为 VARCHAR 并给我 Column length too big 或 Row size too large，或者它变成了 LONGTEXT.

I tried setting the StringLenghtAttribute to something else, 65535, 70000, Int32.MaxValue etc, but it either interpretet it as a VARCHAR and gave me the Column length too big or Row size too large, or it became a LONGTEXT.

问题是:我怎样才能强迫它变成TEXT"?(或 mysql 中的任何其他文本类型)?

Question is: how can I force it to become "TEXT" (or any other text type in mysql)?

我也许可以修改 MaxColumnDefinition 并将其设置为 TEXT 但我假设我永远不会得到 LONGTEXT.

I could perhaps modify the MaxColumnDefinition and set it to TEXT but then I will never get LONGTEXT I assume.

将 MaxColumnDefinition 设置为 TEXT 并没有改变任何事情.

Setting the MaxColumnDefinition to TEXT didn't change a thing.

我可以用属性装饰类，以某种方式指定类型吗?还是太特定于 sql 版本?

Can I decorate the class with an attribute, specifying the type somehow? Or is that too sql-version-specific?

或者也许我应该覆盖 GetColumnDefinition 并实现我自己的逻辑......

Or perhaps I should override the GetColumnDefinition and implement my own logic...

推荐答案

(请注意，此解决方案会产生其他问题，我将在单独的 SO 帖子中提出)

经过更多研究，解决了创建我自己的 StringConverter 的问题，如下所示:

After some more research, it was solved creating my own StringConverter, as can be seen below:

public class MyStringConverter : StringConverter
{
    public override string GetColumnDefinition(int? stringLength)
    {
        if (stringLength.GetValueOrDefault() == StringLengthAttribute.MaxText)
            return MaxColumnDefinition;

        if (stringLength.GetValueOrDefault(StringLength) <= 255)
        {
            return UseUnicode
            ? $"NVARCHAR({stringLength.GetValueOrDefault(StringLength)})"
            : $"VARCHAR({stringLength.GetValueOrDefault(StringLength)})";
        }
        else if (stringLength.GetValueOrDefault(StringLength) <= 65535)
        {
            return $"TEXT";
        }
        else
        {
            return "LONGTEXT";
        }
    }
}

我还建议将默认 StringLength 设置为小于默认 8000 的值:

I also suggest setting the default StringLength to something smaller than the default 8000:

StringConverter converter = OrmLiteConfig.DialectProvider.GetStringConverter();
converter.StringLength = 255;

这样，默认的 string 将是 varchar(255).如果你想让一个特定的字符串属性变成别的东西，那么根据 MyStringConverter 设置属性:

This way, the default string will be varchar(255). If you want to make a specific string property something else, then set the attribute according to the MyStringConverter:

type = typeof(tWorks.Core.CoreCommons.ContactModuleProtocols.SMS.ModuleSettingsSMS);
type.GetProperty(nameof(MyClass.Prop1)).AddAttributes(new StringLengthAttribute(255)); // ==> varchar(255)
type.GetProperty(nameof(MyClass.Prop2)).AddAttributes(new StringLengthAttribute(500)); // ==> TEXT
type.GetProperty(nameof(MyClass.Prop3)).AddAttributes(new StringLengthAttribute(70000)); // ==> LONGTEXT

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