Question 1：Can you use a batch SQL or store procedure to calculating the Number of Days in a Month

　　Answer 1：找出当月的天数
select datepart(dd,dateadd(dd,-1,dateadd(mm,1,cast(cast(year(getdate()) as varchar)+''-''+cast(month(getdate()) as varchar)+''-01'' as datetime))))

　　Question2：Can you use a SQL statement to calculating it!
How can I print "10 to 20" for books that sell for between $10 and $20，"unknown" for books whose price is null, and "other" for all other prices?

　　Answer 2：
　　select bookid,bookname,price=case when price is null then 　　''unknown''
when  price between 10 and 20 then ''10 to 20'' else price end
from books

　　Question3：Can you use a SQL statement to finding duplicate 　　values!
　　How can I find authors with the same last name?
You can use the table authors in datatabase pubs. I want to get the result as below:
Output:
au_lname   number_dups
---------------------------------------- -----------
Ringer  2
(1 row(s) affected)

　　Answer 3
　　select au_lname,number_dups=count(1) from authors group by au_lname

　　Question4：Can you create a cross-tab report in my SQL Server!
　　How can I get the report about sale quality for each store and each quarter and the total sale quality for each quarter at year 1993?

　　You can use the table sales and stores in datatabase pubs.
Table Sales record all sale detail item for each store. Column store_id is the id of each store, ord_date is the order date of each sale item, and column qty is the sale qulity. Table stores record all store information.
I want to get the result look like as below:
Output:

stor_name  Total Qtr1  Qtr2  Qtr3  Qtr4 
---------------------------------------- ----------- ----------- ----------- ----------- -----------
Barnum''s   50 0  50 0  0
Bookbeat   55 25 30 0  0
Doc-U-Mat: Quality Laundry and Books  85 0  85 0  0
Fricative Bookshop  60 35 0  0  25
Total   250   60 165   0  25

Answer 4：用动态SQL实现

　　Question5: The Fastest Way to Recompile All Stored Procedures
　　I have a problem with a database running in SQL Server 6.5 (Service Pack 4). We moved the database (object transfer) from one machine to another last night, and an error (specific to a stored procedure) is cropping up. However, I can''t tell which procedure is causing it. Permissions are granted in all of our stored procedures; is there a way from the isql utility to force all stored procedures to recompile?

　　Tips: sp_recompile can recomplie a store procedure each time

　　Answer 5：在执行存储过程时,使用 with recompile 选项强制编译新的计划；使用sp_recompile系统存储过程强制在下次运行时进行重新编译

　　Question6: How can I add row numbers to my result set?
In database pubs, have a table titles , now I want the result shown as below,each row have a row number, how can you do that?
Result:
line-no  title_id
----------- --------
1  BU1032
2  BU1111
3  BU2075
4  BU7832
5  MC2222
6  MC3021
7  MC3026
8  PC1035
9  PC8888
10 PC9999
11 PS1372
12 PS2091
13 PS2106
14 PS3333
15 PS7777
16 TC3218
17 TC4203
18 TC7777
 
　　Answer 6：
　　--SQL 2005的写法
　　select row_number() as line_no ,title_id from titles
　　--SQL 2000的写法
　　select line_no identity(int,1,1),title_id into #t from titles
　　select * from #t
　　drop table #t