29.09

DECLARE @string NVARCHAR(1000)
DECLARE @word NVARCHAR(50)
DECLARE @space INT
DECLARE @words TABLE (
    word NVARCHAR(50),
    amount INT
)
DECLARE cur CURSOR FOR SELECT mess FROM messages
OPEN cur 
FETCH NEXT FROM cur INTO @string
WHILE @@FETCH_STATUS = 0
BEGIN
    SET @string = LOWER(@string)
    SET @string = @string + ' '
    SET @string = TRANSLATE(@string, '!?.=)(*,-:1234567890', '                    ') ;
    WHILE CHARINDEX('  ', @string) > 0
    BEGIN
        SET @string = REPLACE(@string, '  ', ' ')
    END

    SET @space = CHARINDEX(' ', @string)

    WHILE @space > 0
    BEGIN
        SET @word = SUBSTRING(@string, 1, @space - 1)
        SET @string = SUBSTRING(@string, @space + 1, LEN(@string) - @space + 1)
        
        IF EXISTS (SELECT * FROM @words WHERE word = @word)
        BEGIN
            UPDATE @words
            SET amount = amount + 1
            WHERE word = @word
        END
        ELSE
        BEGIN
            INSERT INTO @words VALUES (@word, 1)
        END

        SET @space = CHARINDEX(' ', @string)
    END

    FETCH NEXT FROM cur INTO @string
END
CLOSE cur
DEALLOCATE cur

SELECT TOP 50 word, amount
FROM @words
ORDER BY amount DESC