NVARCHAR2 Datatype Beginning with Oracle9i, the NVARCHAR2 datatype is redefined to be a Unicode-only datatype. When you create a table with an NVARCHAR2 column, you supply the maximum number of characters it can hold. Oracle subsequently stores each value in the column exactly as you specify it, provided the value does not exceed the column's maximum length.The column's maximum length is determined by the national character set definition. Width specifications of character datatype NVARCHAR2 refer to the number of characters. The maximum column size allowed is 4000 bytes.
而且我们常用varchar或varchar2型的
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varchar2 存放本地化编码方式(如ASCII/GBK)编码的字符串。可以使用像VARCHAR2(3 CHAR)这样的声明，Oracle将留出适当的字节数来容纳基础字符集中的三个字符
是的。
Beginning with Oracle9i, the NVARCHAR2 datatype is redefined to be a Unicode-only datatype. When you create a table with an NVARCHAR2 column, you supply the maximum number of characters it can hold. Oracle subsequently stores each value in the column exactly as you specify it, provided the value does not exceed the column's maximum length.The column's maximum length is determined by the national character set definition. Width specifications of character datatype NVARCHAR2 refer to the number of characters. The maximum column size allowed is 4000 bytes.