摘要: Write a SQL query to delete all duplicate email entries in a table namedPerson, keeping only unique emails based on itssmallestId.+----+--------------... 阅读全文
posted @ 2015-10-21 23:10 Justin.cn 阅读(150) 评论(0) 推荐(0)
摘要: Write a SQL query to rank scores. If there is a tie between two scores, both should have the same ranking. Note that after a tie, the next ranking num... 阅读全文
posted @ 2015-10-21 20:24 Justin.cn 阅读(190) 评论(0) 推荐(0)
摘要: Consecutive NumbersWrite a SQL query to find all numbers that appear at least three times consecutively.+----+-----+| Id | Num |+----+-----+| 1 | 1 ... 阅读全文
posted @ 2015-10-21 20:23 Justin.cn 阅读(187) 评论(0) 推荐(0)