如何在T-SQL中使用两个不同表的值调用Levenshtien函数

CREATE PROCEDURE CalculateLevenshteinDistance
    @string1 NVARCHAR(MAX),
    @string2 NVARCHAR(MAX)
AS
BEGIN
    DECLARE @len1 INT, @len2 INT, @i INT, @j INT, @cost INT, @distance TABLE (i INT, j INT, distance INT)
    
    SET @len1 = LEN(@string1)
    SET @len2 = LEN(@string2)
    
    IF @len1 = 0
    BEGIN
        RETURN @len2
    END
    
    IF @len2 = 0
    BEGIN
        RETURN @len1
    END
    
    SET @i = 0
    SET @j = 0
    
    WHILE @i <= @len1
    BEGIN
        INSERT INTO @distance VALUES (@i, @j, @i)
        SET @i = @i + 1
    END
    
    WHILE @j <= @len2
    BEGIN
        INSERT INTO @distance VALUES (@i, @j, @j)
        SET @j = @j + 1
    END
    
    SET @i = 1
    
    WHILE @i <= @len1
    BEGIN
        SET @j = 1
        
        WHILE @j <= @len2
        BEGIN
            IF SUBSTRING(@string1, @i, 1) = SUBSTRING(@string2, @j, 1)
            BEGIN
                SET @cost = 0
            END
            ELSE
            BEGIN
                SET @cost = 1
            END
            
            INSERT INTO @distance VALUES (@i, @j, 0)
            
            UPDATE @distance
            SET distance = 
                (SELECT MIN(distance + @cost, (SELECT distance FROM @distance WHERE i = @i - 1 AND j = @j) + 1, (SELECT distance FROM @distance WHERE i = @i AND j = @j - 1) + 1))
            WHERE i = @i AND j = @j
            
            SET @j = @j + 1
        END
        
        SET @i = @i + 1
    END
    
    RETURN (SELECT distance FROM @distance WHERE i = @len1 AND j = @len2)
END

DECLARE @string1 NVARCHAR(MAX), @string2 NVARCHAR(MAX), @distance INT

SET @string1 = (SELECT column1 FROM table1 WHERE condition)
SET @string2 = (SELECT column2 FROM table2 WHERE condition)

EXEC @distance = CalculateLevenshteinDistance @string1, @string2

SELECT @distance AS LevenshteinDistance