这是一个小功能,将为您执行“北约编码”:
CREATE FUNCTION dbo.NATOEncode (
@String varchar(max)
)
RETURNS TABLE
WITH SCHEMABINDING
AS
RETURN (
WITH L1 (N) AS (SELECT 1 UNION ALL SELECT 1),
L2 (N) AS (SELECT 1 FROM L1, L1 B),
L3 (N) AS (SELECT 1 FROM L2, L2 B),
L4 (N) AS (SELECT 1 FROM L3, L3 B),
L5 (N) AS (SELECT 1 FROM L4, L4 C),
L6 (N) AS (SELECT 1 FROM L5, L5 C),
Nums (Num) AS (SELECT Row_Number() OVER (ORDER BY (SELECT 1)) FROM L6)
SELECT
NATOString = Substring((
SELECT
Convert(varchar(max), ' ' + D.Word)
FROM
Nums N
INNER JOIN (VALUES
('A', 'Alpha'),
('B', 'Beta'),
('C', 'Charlie'),
('D', 'Delta'),
('E', 'Echo'),
('F', 'Foxtrot'),
('G', 'Golf'),
('H', 'Hotel'),
('I', 'India'),
('J', 'Juliet'),
('K', 'Kilo'),
('L', 'Lima'),
('M', 'Mike'),
('N', 'November'),
('O', 'Oscar'),
('P', 'Papa'),
('Q', 'Quebec'),
('R', 'Romeo'),
('S', 'Sierra'),
('T', 'Tango'),
('U', 'Uniform'),
('V', 'Victor'),
('W', 'Whiskey'),
('X', 'X-Ray'),
('Y', 'Yankee'),
('Z', 'Zulu'),
('0', 'Zero'),
('1', 'One'),
('2', 'Two'),
('3', 'Three'),
('4', 'Four'),
('5', 'Five'),
('6', 'Six'),
('7', 'Seven'),
('8', 'Eight'),
('9', 'Niner')
) D (Digit, Word)
ON Substring(@String, N.Num, 1) = D.Digit
WHERE
N.Num <= Len(@String)
FOR XML PATH(''), TYPE
).value('.[1]', 'varchar(max)'), 2, 2147483647)
);
这个函数甚至可以处理很长的字符串,并且性能很好(我对一个 100,000 个字符的字符串运行它,它在 589 毫秒内返回)。以下是如何使用它的示例:
SELECT NATOString FROM dbo.NATOEncode('LD-23DSP-1430');
-- Output: Lima Delta Two Three Delta Sierra Papa One Four Three Zero
我故意将其设为表值函数,因此如果您一次针对多行运行它,它可以内联到查询中,只需使用CROSS APPLY
或将上面的示例包装在括号中以将其用作SELECT
子句中的值(您可以放一个函数参数位置中的列名)。