在SQL Server中将字符串中每个单词的第一个字母大写的最佳方法是什么？

Question

在SQL Server中将字符串中每个单词的第一个字母大写的最佳方法是什么？

Answer 1

来自http://www.sql-server-helper.com/functions/initcap.aspx

CREATE FUNCTION [dbo].[InitCap] ( @InputString varchar(4000) ) 
RETURNS VARCHAR(4000)
AS
BEGIN

DECLARE @Index          INT
DECLARE @Char           CHAR(1)
DECLARE @PrevChar       CHAR(1)
DECLARE @OutputString   VARCHAR(255)

SET @OutputString = LOWER(@InputString)
SET @Index = 1

WHILE @Index <= LEN(@InputString)
BEGIN
    SET @Char     = SUBSTRING(@InputString, @Index, 1)
    SET @PrevChar = CASE WHEN @Index = 1 THEN ' '
                         ELSE SUBSTRING(@InputString, @Index - 1, 1)
                    END

    IF @PrevChar IN (' ', ';', ':', '!', '?', ',', '.', '_', '-', '/', '&', '''', '(')
    BEGIN
        IF @PrevChar != '''' OR UPPER(@Char) != 'S'
            SET @OutputString = STUFF(@OutputString, @Index, 1, UPPER(@Char))
    END

    SET @Index = @Index + 1
END

RETURN @OutputString

END
GO

这里有一个更简单/更小的(但如果任何行没有空格则不起作用,"传递给RIGHT函数的长度参数无效."):

http://www.devx.com/tips/Tip/17608

Answer 2

作为表值函数：

CREATE FUNCTION dbo.InitCap(@v AS VARCHAR(MAX))
RETURNS TABLE
AS
RETURN 
WITH a AS (
    SELECT (
        SELECT UPPER(LEFT(value, 1)) + LOWER(SUBSTRING(value, 2, LEN(value))) AS 'data()'
        FROM string_split(@v, ' ')
        ORDER BY CHARINDEX(value,@v)
        FOR XML PATH (''), TYPE) ret)

SELECT CAST(a.ret AS varchar(MAX)) ret from a
GO

请注意，string_split需要COMPATIBILITY_LEVEL130。