共用方式為


NCHAR (Transact-SQL)

依照 Unicode 標準所定義,傳回含指定整數碼的 Unicode 字元。

主題連結圖示Transact-SQL 語法慣例

語法

NCHAR ( integer_expression )

引數

integer_expression

這是一個 0 至 65535 的正整數。如果指定了這個範圍以外的值,便會傳回 NULL。

傳回類型

nchar(1)

範例

A. 使用 NCHAR 和 UNICODE

下列範例會利用 UNICODENCHAR 函數來列印 København 字元字串第二個字元的 UNICODE 值和 NCHAR (Unicode 字元),以及列印實際的第二個字元字串 ?

DECLARE @nstring nchar(8)
SET @nstring = N'København'
SELECT UNICODE(SUBSTRING(@nstring, 2, 1)), 
   NCHAR(UNICODE(SUBSTRING(@nstring, 2, 1)))
GO

以下為結果集: 

----------- - 
248         ?1 row(s) affected)

B. 使用 SUBSTRING、UNICODE、CONVERT 和 NCHAR

下列範例會利用 SUBSTRINGUNICODECONVERTNCHAR 函數來列印 København 字串中的字元數目、Unicode 字元,以及各字元的 UNICODE 值。

-- The @position variable holds the position of the character currently
-- being processed. The @nstring variable is the Unicode character 
-- string to process.
DECLARE @position int, @nstring nchar(9)
-- Initialize the current position variable to the first character in 
-- the string.
SET @position = 1
-- Initialize the character string variable to the string to process.
-- Notice that there is an N before the start of the string. This 
-- indicates that the data following the N is Unicode data.
SET @nstring = N'København'
-- Print the character number of the position of the string you are at, 
-- the actual Unicode character you are processing, and the UNICODE 
-- value for this particular character.
PRINT 'Character #' + ' ' + 'Unicode Character' + ' ' + 'UNICODE Value'
WHILE @position <= DATALENGTH(@nstring)
   BEGIN
   SELECT @position, 
      NCHAR(UNICODE(SUBSTRING(@nstring, @position, 1))),
      CONVERT(NCHAR(17), SUBSTRING(@nstring, @position, 1)),
      UNICODE(SUBSTRING(@nstring, @position, 1))
   SELECT @position = @position + 1
   END
GO

以下為結果集: 

Character # Unicode Character UNICODE Value
                                               
----------- ---- ----------------- ----------- 
1           K    K                 75

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
2           ?   ?                248

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
3           b    b                 98

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
4           e    e                 101

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
5           n    n                 110

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
6           h    h                 104

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
7           a    a                 97

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
8           v    v                 118

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
9           n    n                 110

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
10          NULL                   NULL

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
11          NULL                   NULL

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
12          NULL                   NULL

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
13          NULL                   NULL

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
14          NULL                   NULL

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
15          NULL                   NULL

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
16          NULL                   NULL

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
17          NULL                   NULL

(1 row(s) affected)

                                               
----------- ---- ----------------- ----------- 
18          NULL                   NULL

(1 row(s) affected)

請參閱

參考

資料類型 (Transact-SQL)
字串函數 (Transact-SQL)
UNICODE (Transact-SQL)

說明及資訊

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