Question

Oracle查询语句

SQL query demonstrating the use of an SQL function
SQL query using a subquery (inner query must use a join)
SQL query which demonstrates an outer join (must have data which shows
mismatches)
SQL query that creates a view using a join of at least two tables.
SQL query that displays the contents of a view.
SQL query to create an index and data dictionary proof of creation
SQL top-n query
请问这几个句子分别要我查什么
希望尽量给出例句
多谢

Answer 1

SQL query demonstrating the use of an SQL function
编写一个函数
SQL query using a subquery (inner query must use a join)
使用嵌套查询 必须使用内查询
SQL query which demonstrates an outer join (must have data which shows
mismatches)\
使用外连接查询表 必须有数据
SQL query that creates a view using a join of at least two tables.
建一个视图 最少使用2张彪
SQL query that displays the contents of a view.
查询一个视图的内容
SQL query to create an index and data dictionary proof of creation
创建一个索引和数据字典
SQL top-n query
查询前N行数据

追问

能每个给一个例句么

追答

你是什么数据库

1...创建函数:
create or replace function f_1(n number) return number is
r emp%rowtype;
BEGIN
dbms_output.put_line('姓名 薪水');
select * into r from emp where empno=n;
dbms_output.put_line(r.ename||' '||r.sal); --输出结果,需要 set serverout on 才能显示.
return r.sal;
END;
使用函数:
declare
n number;
m number;
begin
n:=&请输入员工号;
m:=f_1(n);
dbms_output.put_line('m的值为 '||m);
end;

删除函数:
DROP FUNCTION ;

2.SELECT * FROM emp WHERE deptno = (select deptno from emp WHERE ename = 'SMITH');
3.SELECT e.ename, e.sal, d.dname FROM emp e, dept d WHERE e.deptno = d.deptno ORDER by e.deptno;
4.create view myview as (SELECT e.ename, e.sal, d.dname FROM emp e, dept d WHERE e.deptno = d.deptno ORDER by e.deptno);
5.select * from myview;
6.create index emp_idx1 on emp (ename, job);
7.select emp.* ,rownum from emp where rownum<=7;

追问

Oracle
结构如图