DIFFERENCE BETWEEN NVARCHAR2(n) AND VARCHAR2(CHAR n)

[SIDDARTHNGOPAL]

Can you help me out by letting me the know the difference in the follwoing declarations of variables(In PL/SQL BLOCKS) or attrbutes (In a table):
NVARCHAR2(n) and
VARCHAR2(CHAR n)

where n is the maximum number of characters that could be accepted

[rahulkoshti]

Reply

Seeee This=====>

Consider the column which must hold up to a maximum of 20 characters and other application which supports multilingual column.Everythi ng works fine until we try of fill the column with 20 two-byte characters
All of a sudden the column is trying to store twice the data it was before and we have a problem.


VARCHAR2(20)
VARCHAR2(20 BYTE)
VARCHAR2(20 CHAR)

Option 1 uses the default length semantics defined by the NLS_LENGTH_SEMA NTICS parameter which defaults to BYTE. Option 2 allows only the specified number of bytes to be stored in the column, regardless of how many characters this represents. Option 3 allows the specified number of characters to be stored in the column regardless of the number of bytes this equates to.