NHibernate：读取 mysql Blob 字段 - 值返回为“System.Byte []”

Question

I have a class with a property:

virtual public string Data { get; set; }

example.hbm.xml binds that to:

<property name="Data" type="string" column="data" ></property>

The table in MySql is created with:

CREATE TABLE `xxx` (
 `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
 `data` blob,
 PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=binary;

I can successfully write to the db and I can see the text in the column written properly.

When I try to read records from this table the value of the 'Data' property is 'System.Byte[]'. Again this is the value of this property. It's type is 'System.String'.

What to do? Thanks in advance for any clues.

I tried charset=UTF8 too.

I also tried type="StringClob" in the mapping file.

Thanks Tymek

Answer 1

You probably need to read and write this as a byte[]. So you're property definition would look like this instead:

public virtual byte[] Data { get; set; }

In addition to this change you will need to change the type in your mapping. I'm not sure what the type. I think it may be blob.

You can easily convert this data to a string if you need to.

Answer 2

I'm no MySQL expert, but you probably want the column type to be text instead of blob .

With that, type="StringClob" should work