計算字元串由幾個單片語成

字元串由幾個單片語成，一般情況之下以空格分隔來計算即可。

實現方法，參考下麵自定義函數：

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- =============================================
-- Author:      Insus.NET
-- Create date: 2019-05-13
-- Update date: 2019-05-13
-- Description: 計算字元串由幾個單片語成
-- =============================================
CREATE FUNCTION [dbo].[svf_WordCount] 
( 
    @InputString NVARCHAR(MAX)
) 
RETURNS INT
AS
BEGIN
    DECLARE @Index INT = 1
    DECLARE @CurrentChar CHAR(1)
    DECLARE @PreviousChar CHAR(1)
    DECLARE @WordCount INT = 0

    WHILE @Index <= LEN(@InputString)
    BEGIN
        SET @CurrentChar = SUBSTRING(@InputString, @Index, 1)
        SET @PreviousChar = SUBSTRING(@InputString, @Index - 1, 1)
            
        IF @PreviousChar = ' ' AND @CurrentChar != ' '                
            SET @WordCount = @WordCount + 1

        SET @Index = @Index + 1
    END
    RETURN @WordCount
END
GO

舉例演示：