当Oracle中VARCHAR2的大小声明为1个字节时，这是什么意思? [英] What does it mean when the size of a VARCHAR2 in Oracle is declared as 1 byte?

问题描述

我知道我可以使用应该包含的字符数来声明 varchar2 .

I know that I can declare a varchar2 using the number of the characters that it should be able to contain.

但是，在我正在使用的Oracle数据库中，我发现一个字段(名为PDF)的定义如下:

However, in an Oracle database on which I am working, I found that a field (named PDF) is defined as follows:

VARCHAR2(1 BYTE)

这是什么意思?它可以包含几个字符?

What does this mean? How many characters can it contain?

另一个相关的问题: VARCHAR 和 VARCHAR2 有什么区别?

Another, related question: What is the difference between a VARCHAR and a VARCHAR2?

推荐答案

您可以将列/变量声明为varchar2(n CHAR)和varchar2(n byte).

You can declare columns/variables as varchar2(n CHAR) and varchar2(n byte).

n CHAR表示变量将包含n个字符.在多字节字符集中，您并不总是知道要存储多少个字节，但是您确实想保证一定数量的字符的存储.

n CHAR means the variable will hold n characters. In multi byte character sets you don't always know how many bytes you want to store, but you do want to garantee the storage of a certain amount of characters.

n个字节仅表示您要存储的字节数.

n bytes means simply the number of bytes you want to store.

不推荐使用varchar.不要使用它. varchar和varchar2有什么区别?

varchar is deprecated. Do not use it. What is the difference between varchar and varchar2?

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