实体框架和字符串作为NCLOB在oracle Db上 [英] Entity Framework and string as NCLOB on oracle Db

问题描述

我有这个模型：

public class Teacher
{
    public int TeacherID { get; set; }
    public string Name { get; set: }
    public string Surname{ get; set; }
}

当Model First运行时，它会创建我的Teachers表和DbSet，但是对于名称和姓氏（它们是字符串），它将NCLOB类型分配给列。
现在，使用NCLOB类型，我不能在我的表上做一些像equals或distincts的操作....

and when Model First run, it creates my Teachers table and DbSet, but for Name and Surname (which are string) it assigns NCLOB type to the column. Now, with NCLOB type I cannot do some operations like equals or distincts on my table....

如何强制MF将columntype设置为varchar

How can I force MF to set columntype to varchar?

推荐答案

我设法解决了将模型中最大字符串长度设置为
的问题

I've managed to solve the issue setting the maximum string lenght into the model

public class Teacher
{
    public int TeacherID { get; set; }

    [StringLength(255, MinimumLength = 3, ErrorMessage = "My Error Message")]
    public string Name { get; set: }

    [StringLength(255, MinimumLength = 3, ErrorMessage = "My Error Message")]
    public string Surname{ get; set; }
}

没有StringLength Orcale创建一个NCLOB字段，最多可以包含4Gb的数据。

Without the StringLength Orcale creates a NCLOB field that can contain up to 4Gb of data.

注意：varchar的最大长度为4000字节，所以我们不能设置2000以上为MaximumLenght（每个字符为Unicode为2个字节）

Note: Maximum lenght for varchar is 4000 bytes, so we cannot set more than 2000 as MaximumLenght (2 byte per character with Unicode)

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