SET ANSI_NULLS ON

GO

SET QUOTED_IDENTIFIER ON

GO

-- =============================================

-- Author:      Insus.NET

-- Create date: 2019-05-13

-- Update date: 2019-05-13

-- Description: 保留一个空格

-- =============================================

CREATE FUNCTION [dbo].[svf_Leave_A_Space]

(

    @InputString NVARCHAR(MAX)

)

RETURNS NVARCHAR(MAX)

AS

BEGIN

    DECLARE @Index INT = 1

    DECLARE @CurrentChar CHAR(1)

    DECLARE @PreviousChar CHAR(1)

    DECLARE @Str NVARCHAR(MAX) = N''

    WHILE @Index <= LEN(@InputString)

    BEGIN

        SET @CurrentChar = SUBSTRING(@InputString, @Index, 1)

        SET @PreviousChar = SUBSTRING(@InputString, @Index - 1, 1)

        IF @CurrentChar != ' ' OR @CurrentChar != @PreviousChar

            SET @Str = @Str + CAST(@CurrentChar AS NVARCHAR(MAX))

        SET @Index = @Index + 1

    END

    RETURN @Str

END

GO