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Description：The Employee table holds all employees including their managers. Every employee has an Id, and there is also a column for the manager Id.G... 阅读全文
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Description： Write a SQL query to get the second highest salary from the Employee table.+----+--------+| Id | Salary |+----+--------+| 1 | 100 ||... 阅读全文
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第一次刷SQL题目感觉还是不错的。这个题目（https://leetcode.com/problems/combine-two-tables/）大概是说把第一张表和第二张表连接起来。而且第二张表中的Person的Address中的属性可能为NULL。这明显就是个左外链接。?123# Write yo... 阅读全文
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Description：Write a SQL query for a report that provides the following information for each person in the Person table, regardless if there is an add... 阅读全文