Note The following examples are based on the pubs database. By default, the Northwind sample database and the pubs sample database are not installed in SQL Server 2005. These databases can be downloaded from the Microsoft Download Center. For more information, visit the following Microsoft Web site:
http://go.microsoft.com/fwlink/?linkid=30196 (http://go.microsoft.com/fwlink/?linkid=30196)
After you download SQL2000SampleDb.msi, extract the sample database scripts by double-clicking SQL2000SampleDb.msi. By default, SQL2000SampleDb.msi will extract the database scripts and a readme file into the following folder:C:\SQL Server 2000 Sample Databases
Follow the instructions in the readme file to run the installation scripts. If you are using SQL Server 2005
We recommend that you use ranking functions that are provided as a new feature in SQL Server 2005. For more information about the ranking functions, visit the following Microsoft Developer Network (MSDN) Web site:http://msdn2.microsoft.com/en-us/library/ms189798.aspx (http://msdn2.microsoft.com/en-us/library/ms189798.aspx)
Example 1
In this example:- Set 1 is authors.
- Set 2 is authors.
- The relationship is "last and first names are greater than."
- You can avoid the duplicate problem by comparing the first + last names to the other first + last names.
- Count the number of times the relationship is fulfilled by count(*).
select rank=count(*), a1.au_lname, a1.au_fname from authors a1, authors a2 where a1.au_lname + a1.au_fname >= a2.au_lname + a2.au_fname group by a1.au_lname, a1.au_fname order by rank
select rank() OVER (ORDER BY a.au_lname, a.au_fname) as rank, a.au_lname, a.au_fname from authors a order by rank
Rank Au_Lname Au_Fname ---- -------------- ----------- 1 Bennet Abraham 2 Blotchet-Halls Reginald 3 Carson Cheryl 4 DeFrance Michel 5 del Castillo Innes 6 Dull Ann 7 Greene Morningstar 8 Green Marjorie 9 Gringlesby Burt 10 Hunter Sheryl 11 Karsen Livia 12 Locksley Charlene 13 MacFeather Stearns 14 McBadden Heather 15 O'Leary Michael 16 Panteley Sylvia 17 Ringer Albert 18 Ringer Anne 19 Smith Meander 20 Straight Dean 21 Stringer Dirk 22 White Johnson 23 Yokomoto Akiko (23 row(s) affected)
Example 2
In this example:- Rank stores by the number of books sold.
- Set 1 is the number of books sold by store: select stor_id, qty=sum(qty) from sales group by stor_id.
- Set 2 is the number of books sold by store: select stor_id, qty=sum(qty) from sales group by stor_id.
- The relationship is "the number of books is greater than."
- To avoid duplicates, you can (as an example) compare price*qty instead of qty.
select rank=count(*), s1.stor_id, qty=sum(s1.qty) from (select stor_id, qty=sum(qty) from sales group by stor_id) s1, (select stor_id, qty=sum(qty) from sales group by stor_id) s2 where s1.qty >= s2.qty group by s1.stor_id order by rank
Rank Stor_Id Qty ---- ------- --- 1 6380 8 2 7896 120 3 8042 240 4 7067 360 5 7066 625 6 7131 780 (6 row(s) affected)
Use the following code in SQL Server 2005.
select row_number() over (order by qty desc) as rank,s1.stor_id,s1.qty from (select stor_id, qty=sum(qty) from sales group by stor_id) as s1
rank stor_id qty ------- ------- ------ 1 7131 130 2 7066 125 3 7067 90 4 8042 80 5 7896 60 6 6380 8 (6 row(s) affected)
Example 3
In this example:- Rank the publishers by their earnings.
- Set 1 is the total sales by publisher:
select t.pub_id, sales=sum(s.qty*t.price) from sales s, titles t where s.title_id=t.title_id and t.price is not null group by t.pub_id
- Set 2 is the total sales by publisher:
select t.pub_id, sales=sum(s.qty*t.price) from sales s, titles t where s.title_id=t.title_id and t.price is not null group by t.pub_id
- The relationship is "earns more money than."
select rank=count(*), s1.pub_id, sales=sum(s1.sales) from (select t.pub_id, sales=sum(s.qty*t.price) from sales s, titles t where s.title_id=t.title_id and t.price is not null group by t.pub_id) s1, (select t.pub_id, sales=sum(s.qty*t.price) from sales s, titles t where s.title_id=t.title_id and t.price is not null group by t.pub_id) s2 where s1.sales>= s2.sales group by s1.pub_id order by rank
Rank Pub_Id Sales ---- ------ -------- 1 0736 1,961.85 2 0877 4,256.20 3 1389 7,760.85 (3 row(s) affected)
Use the following code in SQL Server 2005.
select rank() over (order by sales desc) as rank,s1.pub_id,s1.sales from (select t.pub_id, sales=sum(s.qty*t.price) from sales s inner join titles t on s.title_id=t.title_id where t.price is not null group by t.pub_id) as s1
rank pub_id sales ------- ------ --------- 1 1389 2586.95 2 0877 2128.10 3 0736 1961.85 (3 row(s) affected)
Drawbacks
- Because of the cross join, this is not designed for working with a large number of rows. It works well for hundreds of rows. On large tables, make sure to use an index to avoid large scans.
- This does not work well with duplicate values. When you compare duplicate values, discontinuous row numbering occurs. If this is not the behavior that you want, you can avoid it by hiding the rank column when you insert the result in a spreadsheet; use the spreadsheet numbering instead.
Note If you are using SQL Server 2005, you can use the row_number() function to return the sequential number of a row, regardless of the duplicate rows.
select rank=count(*), s1.title_id, qty=sum(s1.qty) from (select title_id, qty=sum(qty) from sales group by title_id) s1, (select title_id, qty=sum(qty) from sales group by title_id) s2 where s1.qty >= s2.qty group by s1.title_id order by rank
Rank Title_Id Qty ---- -------- ---- 1 MC2222 10 4 BU1032 60 4 BU7832 60 4 PS3333 60 7 PS1372 140 7 TC4203 140 7 TC7777 140 10 BU1111 250 10 PS2106 250 10 PS7777 250 11 PC1035 330 12 BU2075 420 14 MC3021 560 14 TC3218 560 15 PC8888 750 16 PS2091 1728 (16 row(s) affected)
Benefits
- You can use these queries in views and result formatting.
- You can shift the lower-ranked data more to the right.
CREATE VIEW v_pub_rank AS select rank=count(*), s1.title_id, qty=sum(s1.qty) from (select title_id, qty=sum(qty) from sales group by title_id) s1, (select title_id, qty=sum(qty) from sales group by title_id) s2 where s1.qty >= s2.qty group by s1.title_id
select publisher=convert(varchar(20),replicate (' ', power(2,rank)) + pub_id + replicate(' ', 15-power(2,rank))+': '), earnings=qty from v_pub_rank
Publisher Earnings ------------- -------- 0736 : 1,961.85 0877 : 4,256.20 1389 : 7,760.85
CREATE VIEW v_pub_rank AS select rank() over (order by sales) as rank,s1.pub_id,s1.sales from (select t.pub_id, sales=sum(s.qty*t.price) from sales s, titles t where s.title_id=t.title_id and t.price is not null group by t.pub_id) as s1 GO select publisher=convert(varchar(20),replicate (' ', power(2,rank)) + pub_id + replicate(' ', 15-power(2,rank))+': '), earnings=sales from v_pub_rank order by rank GO
publisher earnings -------------------- --------------------- 0736 : 1961.85 0877 : 2128.10 1389 : 2586.95 (3 row(s) affected)
Example 2:
CREATE VIEW v_title_rank AS select rank=count(*), s1.title_id, qty=sum(s1.qty) from (select title_id, qty=sum(qty) from sales group by title_id) s1, (select title_id, qty=sum(qty) from sales group by title_id) s2 where s1.qty >= s2.qty group by s1.title_id
select Book=convert(varchar(45),replicate (' ', 2*rank) + title_id + replicate(' ', 35-2*rank)+': '), qty from v_title_rank order by rank
Book Qty ------------------------------------------- ---- MC2222 : 10 BU1032 : 60 BU7832 : 60 PS3333 : 60 PS1372 : 140 TC4203 : 140 TC7777 : 140 BU1111 : 250 PS2106 : 250 PS7777 : 250 PC1035 : 330 BU2075 : 420 MC3021 : 560 TC3218 : 560 PC8888 : 750 PS2091 : 1728 (16 row(s) affected)
CREATE VIEW v_title_rank AS select rank() over (order by qty) as rank, s1.title_id,s1.qty from (select title_id, qty=sum(qty) from sales group by title_id) as s1 GO select Book=convert(varchar(45),replicate (' ', 2*rank) + title_id + replicate(' ', 35-2*rank)+': '), qty from v_title_rank order by rank GO
Book qty --------------------------------------------- ----------- MC2222 : 10 BU1032 : 15 BU7832 : 15 PS3333 : 15 TC4203 : 20 TC7777 : 20 PS1372 : 20 BU1111 : 25 PS7777 : 25 PS2106 : 25 PC1035 : 30 BU2075 : 35 MC3021 : 40 TC3218 : 40 PC8888 : 50 PS2091 : 108 (16 row(s) affected) http://support.microsoft.com/default.aspx?scid=http://support.microsoft.com:80/support/kb/articles/q186/1/33.asp&NoWebContent=1&NoWebContent=1
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