UNICODE (Transact-SQL)
按照 Unicode 标准的定义，返回输入表达式的第一个字符的整数值。
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语法
UNICODE ( 'ncharacter_expression' )
参数
- 'ncharacter_expression'
nchar 或 nvarchar 表达式。
返回类型
int
示例
A. 使用 UNICODE 和 NCHAR 函数
以下示例使用 UNICODE 和 NCHAR 函数输出 Åkergatan 24 字符串中第一个字符的 UNICODE 值，并输出实际的第一个字符 Å。
DECLARE @nstring nchar(12)
SET @nstring = N'Åkergatan 24'
SELECT UNICODE(@nstring), NCHAR(UNICODE(@nstring))
下面是结果集：
----------- -
197 Å
B. 使用 SUBSTRING、UNICODE 和 CONVERT
下面的示例使用 SUBSTRING、UNICODE 和 CONVERT 函数输出 Åkergatan 24 字符串中每个字符的字符号、Unicode 字符和 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(12)
-- 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, which
-- indicates that the data following the N is Unicode data.
SET @nstring = N'Åkergatan 24'
-- 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)
-- While these are still characters in the character string,
BEGIN
SELECT @position,
CONVERT(char(17), SUBSTRING(@nstring, @position, 1)),
UNICODE(SUBSTRING(@nstring, @position, 1))
SELECT @position = @position + 1
END
下面是结果集：
Character # Unicode Character UNICODE Value
----------- ----------------- -----------
1 Å 197
----------- ----------------- -----------
2 k 107
----------- ----------------- -----------
3 e 101
----------- ----------------- -----------
4 r 114
----------- ----------------- -----------
5 g 103
----------- ----------------- -----------
6 a 97
----------- ----------------- -----------
7 t 116
----------- ----------------- -----------
8 a 97
----------- ----------------- -----------
9 n 110
----------- ----------------- -----------
10 32
----------- ----------------- -----------
11 2 50
----------- ----------------- -----------
12 4 52