什么时候应该使用备忘录字段而不是MS Access中的文本字段 [英] When should a memo field be used as opposed to a text field in MS Access

问题描述

在什么时候应该考虑使用备忘录字段类型，而不是MS Access数据库中的文本字段类型？我意识到主要考虑的是字段的长度，因为文本限制为255个字符，并且备忘录字段确实不能在查询条件中使用，但还有其他注意事项？文本字段为每个记录保留空间，但是备注字段只能输入文本的空格。

At what point should one consider using the memo field type as opposed to the text field type in a MS Access database? I realize the primary consideration is the length of the field, as text is limited to 255 chars, and the memo field really can't be used in a query criteria, but are there other considerations? The text field reserves the space for every record, but the memo field only uses space for the text entered?

推荐答案

长度作为主要考虑。对我来说，这更像是只有的考虑。如果该字段必须不超过255个字符，则它将是文本而不是备注类型。

You mentioned text length as the primary consideration. For me, that is more like the only consideration. If the field has to hold no more than 255 characters, it will be text instead of memo type.

我记得的唯一例外是与每个记录4000字符限制。请参阅访问2010年规范：

The only exception I can remember was bumping up against the per-record 4,000 character limit. See Access 2010 specifications:

字段的UnicodeCompression属性是一个记录中的字符数（不包括备忘录和OLE对象
字段）设置为
是

Number of characters in a record (excluding Memo and OLE Object fields) when the UnicodeCompression property of the fields is set to Yes

4,000

由于备注字段不要反对这个限制，我只做了一些字段备忘录，只是将记录的剩余部分数字保持在极限内。

Since memo fields do not count against that limit, I made some fields memo simply to keep the remainder of the record's character count within the limit.

但这是一次性的情况。

But that was a one-time situation.

如果要存储Access的富文本，则需要备注字段。 （谢谢， Gord 。）

If you want to store Access' "rich text", you would want a memo field. (Thanks, Gord.)

在我的头顶，我不能想到任何其他原因如果文字满足，请选择备忘录。

Off the top of my head, I can't think of any other reasons to choose memo when text would suffice.

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