1、查询字段web_url中以符号"/"结尾的数据
  
   SELECT * FROM table_name WHERE web_url REGEXP '/$';

2、把字段web_url结尾的符号"/"删除

UPDATE
    table_name
SET
    web_url = REPLACE(
        web_url,
        web_url,
        SUBSTRING(web_url, 1, LENGTH(web_url) - 1)
    )
WHERE
web_url REGEXP '/$'