-- 如果你想根据某个字段(比如 Salary)进行排序,并选择前 5 个 SELECT TOP 5 Name, Salary FROM Employees ORDER BY Salary DESC; -- 这将返回薪水最高的前 5 个员工 -- 或者,你也可以使用百分比来选择顶部的记录 -- 例如,选择前 10% 的员工(注意:这在 SQL Server 2012 及更高版本中才支持) SELECT ...
CREATE TRIGGER example_trigger AFTER INSERT ON COMPANY FOR EACH ROW EXECUTE PROCEDURE auditlogfunc();/插入数据触发触发器/ INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (1, ‘张三’, 32, ‘济南’, 20000.00 )/查询数据库中的所有触发器/ select * from pg_trigger/删除触发器/ drop tr...
SQL Server Interview Questions and Answers MySQL Interview Questions DB2 Interview Questions and Answers PL/SQL Interview Questions and Answers Oracle DBA Interview Questions and Answers Top 35 Database Testing Interview Questions and Answers How to Find the Second Highest Salary in SQLSQL...
SQL USEAdventureWorks2022; GOSELECTTOP (5)PERCENTJobTitle, HireDateFROMHumanResources.EmployeeORDERBYHireDateDESC; GO Include tie values A. Use WITH TIES to include rows that match the values in the last row The following example gets the top10percent of all employees with the highest salary an...
SQL 复制 ;WITH cte AS ( SELECT TOP(25)employee_id,first_name,salary FROM employees ORDER BY salary DESC --must need ) SELECT * FROM cte ;WITH cte AS ( SELECT employee_id,first_name,salary, ROW_NUMBER()OVER(ORDER BY salary DESC) RowNum FROM employees ) SELECT * FROM cte WHERE RowN...
11. Hvad er COALESCE i SQL Server? COALESCE bruges til at returnere det første ikke-nul udtryk i argumenterne. Denne funktion bruges til at returnere en ikke-nul fra mere end én kolonne i argumenterne. Eksempel - Select COALESCE(empno, empname, salary) from employee; ...
47、分析select emp_name form employee where salary > 3000 在此语句中若salary是Float类型的,则优化器对其进行优化为Convert(float,3000),因为3000是个整数,我们应在编程时使用3000.0而不要等运行时让DBMS进行转化。同样字符和整型数据的转换。 48、查询的关联同写的顺序 ...
How to Find the Second Highest Salary in SQL ByAkshay|Last updated on October 3, 2024|55416 Views Did You Know? PL/SQLcode can include comments inside it starting with /* and ending with */ like in C programming language. This allows developers to document their code. ...
ALTER TABLE employees ADD COLUMN salary DECIMAL(10, 2); Powered By 10. Was ist eine temporäre Tabelle in SQL? Eine temporäre Tabelle existiert nur während der aktuellen Datenbanksitzung. Sobald wir die Sitzung schließen, wird die Tabelle gelöscht. In dieser Art von Tabelle k...
3.哈希联接 哈希联接有两种输入:生成输入和探测输入。查询优化器指派这些角色,使两个输入中较小的那个作为生成输入。 哈希联接用于多种设置匹配操作:内部联接;左外部联接、右外部联接和完全外部联接;左半联接和右半联接;交集;联合和差异。此外,哈希联接的某种变形可以进行重复删除和分组,例如SUM(salary) GROUP BY dep...