get off

levenshtein.sql

@@ -1,70 +0,0 @@
--- Levenshtein function
--- Source: https://openquery.com.au/blog/levenshtein-mysql-stored-function
--- Levenshtein reference: http://en.wikipedia.org/wiki/Levenshtein_distance
-
--- Arjen note: because the levenshtein value is encoded in a byte array, distance cannot exceed 255;
--- thus the maximum string length this implementation can handle is also limited to 255 characters.
-
-DELIMITER $$
-DROP FUNCTION IF EXISTS LEVENSHTEIN $$
-CREATE FUNCTION LEVENSHTEIN(s1 VARCHAR(255) CHARACTER SET utf8, s2 VARCHAR(255) CHARACTER SET utf8)
-  RETURNS INT
-  DETERMINISTIC
-  BEGIN
-    DECLARE s1_len, s2_len, i, j, c, c_temp, cost INT;
-    DECLARE s1_char CHAR CHARACTER SET utf8;
-    -- max strlen=255 for this function
-    DECLARE cv0, cv1 VARBINARY(256);
-
-    SET s1_len = CHAR_LENGTH(s1),
-        s2_len = CHAR_LENGTH(s2),
-        cv1 = 0x00,
-        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);
-    END IF;
-
-    WHILE (j <= s2_len) DO
-      SET cv1 = CONCAT(cv1, CHAR(j)),
-          j = j + 1;
-    END WHILE;
-
-    WHILE (i <= s1_len) DO
-      SET s1_char = SUBSTRING(s1, i, 1),
-          c = i,
-          cv0 = CHAR(i),
-          j = 1;
-
-      WHILE (j <= s2_len) DO
-        SET c = c + 1,
-            cost = IF(s1_char = SUBSTRING(s2, j, 1), 0, 1);
-
-        SET c_temp = ORD(SUBSTRING(cv1, j, 1)) + cost;
-        IF (c > c_temp) THEN
-          SET c = c_temp;
-        END IF;
-
-        SET c_temp = ORD(SUBSTRING(cv1, j+1, 1)) + 1;
-        IF (c > c_temp) THEN
-          SET c = c_temp;
-        END IF;
-
-        SET cv0 = CONCAT(cv0, CHAR(c)),
-            j = j + 1;
-      END WHILE;
-
-      SET cv1 = cv0,
-          i = i + 1;
-    END WHILE;
-
-    RETURN (c);
-  END $$
-
-DELIMITER ;