1、参考别人的相似度函数
- CREATE FUNCTION levenshtein_distance(s1 VARCHAR(255), s2 VARCHAR(255))
- RETURNS INT
- DETERMINISTIC
- BEGIN
- DECLARE s1_len, s2_len, i, j, c,cost,cmin INT;
- DECLARE s1_char CHAR;
- DECLARE cv0, cv1 VARCHAR(255);
- SET s1_len = CHAR_LENGTH(s1), s2_len = CHAR_LENGTH(s2), cv1 = '', j = 1, i = 1, c = 0;
- IF s1 = s2 THEN
- RETURN 0;
- ELSEIF s1_len = 0 THEN
- RETURN s2_len;
- ELSEIF s2_len = 0 THEN
- RETURN s1_len;
- ELSE
- WHILE j <= s2_len DO
- SET cv1 = CONCAT(cv1, UNHEX(HEX(j))), j = j + 1;
- END WHILE;
- WHILE i <= s1_len DO
- SET s1_char = SUBSTRING(s1, i, 1), c = i, cv0 = UNHEX(HEX(i)), j = 1;
- WHILE j <= s2_len DO
- SET c = c + 1;
- IF s1_char = SUBSTRING(s2, j, 1) THEN
- SET cost = 0;
- ELSE
- SET cost = 1;
- END IF;
- SET cmin = CONV(HEX(SUBSTRING(cv1, j, 1)), 16, 10) + cost;
- SET c = IF(c > cmin, cmin, c) + 1;
- SET cv0 = CONCAT(cv0, UNHEX(HEX(c))), j = j + 1;
- END WHILE;
- SET cv1 = cv0, i = i + 1;
- END WHILE;
- END IF;
- RETURN c;
- END;
2、使用
select * from com_base_shangpin ORDER BY levenshtein_distance(spdm, '000000') ASC LIMIT 1000;
用是能用,就是数据多了超级慢