/******************************************************************************
 * Author: iret
 * Desc: T-SQL Extractor
 *           Extract the comments and blanks and tabs from the SQL statement
 * 为了比较两个存储过程，或者SQL语句是否一致，抽空写了一个可以删除T-SQL 语句中的注释和空格的脚本，挺精致的样子。
 * Created Date: 2004/10/21
 ******************************************************************************/

DECLARE @script VARCHAR(8000), @extractedScript VARCHAR(4000)
SET @script = ''
/*从系统表获取存储过程的脚本*/
SELECT @script = @script + [text]
FROM syscomments, sysobjects
WHERE
    syscomments.[id] = sysobjects.[id] AND sysobjects.[name] LIKE '%campa_AppSegment'

/*标志符*/
DECLARE @InLineCommented BIT, @InSectionCommented BIT, @InString BIT, @position INT

/*当前字符*/
DECLARE @curChar INT

/*前一个字符*/
DECLARE @preChar INT

SET @InLineCommented = 0
SET @InSectionCommented = 0
SET @InString = 0

SET @extractedScript = ''
SET @position = 1
SET @preChar = null

WHILE @position <= DATALENGTH(@script)
BEGIN
    --获取当前字符
    SET @curChar = ASCII(SUBSTRING(@script, @position, 1))
    IF @preChar = ASCII('/') AND @curChar = ASCII('*') AND @InLineCommented = 0 AND @InString = 0
    BEGIN
        -- SET the sign in section comment
        SET @InSectionCommented = 1

         --pop the / char
         SET @extractedScript = substring(@extractedScript,1,len(@extractedScript)-1)

         SET @preChar = @curChar
         SET @position = @position + 1
         CONTINUE
    END

    IF @preChar = ASCII('*') AND @curChar = ASCII('/') AND @InLineCommented = 0 AND @InString = 0
    BEGIN
         SET @InSectionCommented = 0
         SET @preChar = @curChar
         SET @position = @position + 1
         CONTINUE
    END

    IF @preChar = ASCII('-') AND @curChar = ASCII('-') AND @InSectionCommented = 0 AND @InString = 0
    BEGIN
         SET @InLineCommented = 1

         --pop the / char
         SET @extractedScript = substring(@extractedScript,1,len(@extractedScript)-1)

         SET @preChar = @curChar
         SET @position = @position + 1
         CONTINUE
    END

    IF @curChar = ASCII('''') AND @InString = 0 AND @InSectionCommented = 0 AND @InLineCommented = 0
    BEGIN
         SET @InString = 1
    END

    IF @inString = 1 AND @curChar = ASCII('''')
    BEGIN
         IF ASCII(SUBSTRING(@script, @position+1, 1))= ASCII('''')
         BEGIN  
              SET @extractedScript = @extractedScript + ''''
              SET @position = @position + 1
        END
        ELSE
         BEGIN
              SET @InString = 0  
         END
    END

    IF @InSectionCommented = 1
    BEGIN
         SET @preChar = @curChar
         SET @position = @position + 1
         CONTINUE
    END

    IF @InLineCommented = 1
    BEGIN
        -- if meets the end of the line set the InLineCommented to false
        IF @curChar = 10 AND @preChar = 13
        BEGIN
           SET @InLineCommented = 0
        END

         SET @preChar = @curChar
         SET @position = @position + 1
         CONTINUE
    END

    IF @curChar = ASCII(' ') OR @curChar = 10 OR @curChar =13 OR @curChar = ASCII(' ') OR @curChar = 32
    BEGIN
         SET @preChar = @curChar
         SET @position = @position + 1
         CONTINUE
    END

    SET @extractedScript = @extractedScript + CHAR(@curChar)
    SET @preChar = @curChar
    SET @position = @position + 1
END

-- print the result script
SELECT @extractedScript