SqlServer和Oracle中一些常用的sql语句10 特殊应用

--482,ORACLE / sql SERVER
--订购数量超过平均值的书籍
WITH Orders_Book
AS
  (
  SELECT Book_Name,SUM(Qty) Book_Qty
  FROM Orders
  GROUP BY Book_Name
  )
SELECT *
FROM Orders_Book
WHERE Book_Qty >
      (
      SELECT AVG(Book_Qty)
      FROM Orders_Book
      )

--递归 产生连续数列1至10000  
WITH Tally(N)
AS
  (
  SELECT 1 N       
  --FROM DAUL       -- ORACLE
  UNION ALL        
  --2.递归区块
  SELECT N+1     
  FROM Tally        
  WHERE N<=10000  
  ) 
  SELECT N
FROM TALLY
OPTION (MAXRECURSION 10000)  --sql SERVER设定深度    

--490,sql SERVER
--随机抽出3笔员工数据
SELECT TOP 3 
    E.Emp_Id,E.Emp_Name,E.Dept_Id
FROM Employees E
ORDER BY NEWID()       


--491,sql SERVER
--在I100和I200部门中随机抽出一名员工(子分组中各抽出N笔)
SELECT E.Emp_Id,E.Dept_Id  
FROM 
  (
  SELECT Emp_Id,Emp_Name,Dept_Id,ROW_NUMBER() OVER (PARTITION BY Dept_Id 
                                      ORDER BY NEWID()) RowNo
  FROM Employees
  WHERE Dept_Id IN ('I100','I200')
  ) E
WHERE E.RowNo <=1 


--492,ORACLE
--随机抽出3笔员工数据
SELECT Emp_Id,Dept_Id
FROM
  (
    SELECT *
    FROM Employees
    ORDER BY DBMS_RANDOM.VALUE()
  )
WHERE ROWNUM<=3 

--493,ORACLE
--在I100和I200部门中随机抽出一名员工(子分组中各抽出N笔)
SELECT E.Emp_Id,E.Dept_Id 
FROM 
(
SELECT Emp_Id,ROW_NUMBER() 
         OVER (PARTITION BY Dept_Id 
               ORDER BY DBMS_RANDOM.VALUE()) RowNo
   FROM Employees
   WHERE Dept_Id IN ('I100','I200')
   ) E
WHERE E.RowNo <=1 


--495,sql SERVER
--以符号分割的字符串 分拆成table返回,含一字段 Column_Value
create function [dbo].[m_split](@c varchar(2000),@split varchar(2))  
    returns @t table(col varchar(200))  
as  
begin  
      while(charindex(@split,@c)<>0)  
        begin  
          insert @t(col) values (substring(@c,1,charindex(@split,@c)-1))  
          set @c = stuff(@c,@c),'')  
        end  
      insert @t(col) values (@c)  
      return  
end

--测试
select * from [dbo].[m_split]('1,2,3',',')



--496,ORACLE
--以符号分割的字符串 分拆成table返回,含一字段 Column_Value
CREATE OR REPLACE TYPE split_tbl AS TABLE OF VARCHAR2(32767);

--测试1
SELECT Column_Value
FROM TABLE(Split_Tbl(1,3))

--测试2
SELECT Column_Value
FROM TABLE(Split_Tbl('A','B','C'))