wcur LOCATE +

w字符串处理

 DROP PROCEDURE IF EXISTS w_unique;
 DELIMITER /w/
 CREATE PROCEDURE w_unique()
 BEGIN
   DECLARE done INT DEFAULT FALSE;
   DECLARE w_wmax INT;
   DECLARE w_grab_review_url VARCHAR(256);
   DECLARE wcur CURSOR FOR SELECT MAX(grab_tab_review_pk) AS  wmax, grab_review_url FROM grab_tab_review WHERE LENGTH(grab_review_url)>0 GROUP BY grab_review_url;
   DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

   OPEN wcur;
   read_loop: LOOP
     FETCH wcur INTO w_wmax, w_grab_review_url;
     IF done THEN LEAVE read_loop;
     END IF;
         SET @wtmp = CONCAT('DELETE FROM grab_tab_review WHERE grab_tab_review_pk!=',w_wmax,' AND grab_review_url="',w_grab_review_url,'"');
         PREPARE  stmt FROM @wtmp ;
         EXECUTE  stmt ;
         DROP PREPARE stmt;
   END LOOP;
   CLOSE wcur;
 END/w/
 DELIMITER;
 CALL w_unique();

 DROP PROCEDURE IF EXISTS w_self_update;
 DELIMITER /w/
 CREATE PROCEDURE w_self_update(w_arr  VARCHAR(36))
 BEGIN
   DECLARE done INT DEFAULT FALSE;
   DECLARE w_grab_tab_review_pk INT;
   DECLARE w_grab_review_url VARCHAR(256);
   DECLARE wcur CURSOR FOR SELECT grab_tab_review_pk, grab_review_url FROM grab_tab_review WHERE LENGTH(grab_review_url)>0;
   DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

   OPEN wcur;
   read_loop: LOOP
     FETCH wcur INTO w_grab_tab_review_pk, w_grab_review_url,w_countrycode;
     IF done THEN LEAVE read_loop;
     END IF;
         SET @w=LOCATE(w_arr,w_grab_review_url);
         SET @wb=LOCATE('/ref=',w_grab_review_url);
         SET @wstr=SUBSTR(w_grab_review_url,@w + LENGTH(w_arr),@wb - @w - LENGTH(w_arr));
         SET @wtmp = CONCAT('UPDATE grab_tab_review ',' SET amz_review_id="',@wstr,'" WHERE grab_tab_review_pk=',w_grab_tab_review_pk);
         PREPARE  stmt FROM @wtmp ;
         IF @w>0 THEN EXECUTE  stmt ;
     END IF;
         DROP PREPARE stmt;
   END LOOP;
   CLOSE wcur;
 END/w/
 DELIMITER;
 CALL w_self_update('-reviews/');
 CALL w_self_update('-review/');

 https://www.amazon.com.mx/review/R1OR2BGFHA44LE/ref=cm_cr_dp_title?ie=UTF8&ASIN=B0196IK0OM&channel=detail-glance&nodeID=9482690011&store=software
 https://www.amazon.com.mx/gp/customer-reviews/R1OR2BGFHA44LE/ref=cm_cr_dp_title?ie=UTF8&ASIN=B0196IK0OM&channel=detail-glance&nodeID=9482690011&store=software
 ===>
 R1OR2BGFHA44LE

 SELECT grab_review_url FROM grab_tab_review WHERE grab_tab_review_pk=123456;

 SELECT
     SUBSTR(
         (
             SELECT
                 grab_review_url
             FROM
                 grab_tab_review
             WHERE
                 grab_tab_review_pk = 123456
         ),
         LOCATE(
             '-reviews/',
             (
                 SELECT
                     grab_review_url
                 FROM
                     grab_tab_review
                 WHERE
                     grab_tab_review_pk = 123456
             )
         ) + LENGTH('-reviews/'),
         LOCATE(
             '/ref=',
             (
                 SELECT
                     grab_review_url
                 FROM
                     grab_tab_review
                 WHERE
                     grab_tab_review_pk = 123456
             )
         ) - LOCATE(
             '-reviews/',
             (
                 SELECT
                     grab_review_url
                 FROM
                     grab_tab_review
                 WHERE
                     grab_tab_review_pk = 123456
             )
         ) - LENGTH('-reviews/')
     );