有人可以幫助我通過別名和處理空值組嗎？

我想使用50個頁面範圍來排列頁面計數。我試圖根據他們的頁面範圍排列頁數來顯示書籍。這意味着任何書頁數500-549的排名都相同。頁數550-599有相同的排名;頁數600-649具有相同的排名; 頁數650-699有相同的排名等我不能跳過排名數字。我將如何解決這個問題？有人可以幫助我通過別名和處理空值組嗎？

不確定這是否正確。這是我到目前爲止：

set @rownum:= 0; 
select page_count, Ranking 
from(
SELECT case 
when page_count between 0 and 49 then '0 - 49' 
when page_count between 50 and 99 then '50 - 99' 
when page_count between 100 and 149 then '100 - 149' 
when page_count between 150 and 199 then '150 - 199' 
when page_count between 200 and 249 then '200 - 249' 
when page_count between 250 and 299 then '250 - 299' 
when page_count between 300 and 349 then '300 - 349' 
when page_count between 350 and 399 then '350 - 399' 
when page_count between 400 and 449 then '400 - 449' 
when page_count between 450 and 499 then '450 - 499' 
when page_count between 500 and 549 then '500 - 549' 
when page_count between 550 and 599 then '550 - 599' 
when page_count between 600 and 649 then '600 - 649' 
when page_count > 650 then 'Page Count over 650' 
end as page_count 
, 
    @rownum:= @rownum + 1 as Ranking 
    from a_bkinfo.books 
)tbl 
    group by page_count;

爲什麼50-99不合適？

下面是表：

create table a_bkinfo.books (
    book_id   integer   not null 
    , title    varchar(75)  not null 
    , publ_id   integer   null 
    , year_publd  integer   not null 
    , isbn    varchar(17)  null 
    , page_count  integer   null 
    , list_price  numeric(6,2)  null 
    , constraint bk_books_pk    primary key (book_id) 
    , constraint bk_books_publ_fk  foreign key(publ_id) 
       references a_bkinfo.publishers (publ_id) 
    , constraint book_id_range   check (book_id > 1000) 
    , constraint bk_page_count_ck  check (page_count >= 0) 
    , constraint bk_price_ck    check (list_price >= 0)    
    , constraint bk_books_year_ck  check (year_publd >= 1850) 
)engine = INNODB; 

    And here are the inserts: 
-- books 
insert into a_bkinfo.books values (1101, 'Programming SQL Server with VB.NET',    9000, 2002, '0735615357', 300, 59.99); 
insert into a_bkinfo.books values (1102, 'Practical Standards for VB.NET',     9000, 2003, '0735613568', 250, 49.99); 
insert into a_bkinfo.books values (1103, 'Selected Poems',         9456, 1949, null,   125, 12.00); 
insert into a_bkinfo.books values (1104, 'Sibley Guide to Bird Life and Behavior',   9102, 2001, '0679451234', 604, 45.00); 
insert into a_bkinfo.books values (1105, 'SQL:1999 Relational Language Concepts',   9745, 2002, '1558604561', 450, 59.95); 
insert into a_bkinfo.books values (1106, 'SQL for Smarties',        9745, 1995, '1558603239', 250, 29.00); 
insert into a_bkinfo.books values (1107, 'SQL Puzzles and Answers',       9745, 1997, '1558604537', 325, 25.00); 
insert into a_bkinfo.books values (1108, 'Database Systems',        9325, 1996, null,   680, 39.95); 
insert into a_bkinfo.books values (1109, 'Intro to DB Systems-7th Ed',      9325, 2000, '0201385902', 650, 80.00); 
insert into a_bkinfo.books values (1110, 'Adv SQL:1999 Object_Relational Features',   9745, 2002, '1558606077', 520, 59.95); 


insert into a_bkinfo.books values (1128, 'Temporal Data and the Relational Model',   9325, 2003, 'na',   275, 49.95); 
insert into a_bkinfo.books values (1133, 'Leaves of Grass',         9623, 1902, null,   125, 19.95); 
insert into a_bkinfo.books values (1142, 'Relational Database Theory',      9521, 1993, null,   879, 95.00); 
insert into a_bkinfo.books values (1161, 'SQL Programming Style',       9745, 2005, '0120887975', 780, 35.00); 
insert into a_bkinfo.books values (1162, 'Trees and Hierarchies',       9745, 2004, '1558609202', 350, 35.00); 
insert into a_bkinfo.books values (1180, 'MySQL Database Design and Tuning',    9825, 2005, '9780672234650', 400, 49.99); 
insert into a_bkinfo.books values (1175, 'MySQL in a Nutshell',        9822, 2008, '9780596514331', 538, 34.99); 
insert into a_bkinfo.books values (1182, 'MySQL Cookbook',         9822, 2007, '9780596527082', 918, 49.99); 
insert into a_bkinfo.books values (1185, 'MySQL Stored Procedures',       9822, 2007, '9780596100896', 595, 49.99); 
insert into a_bkinfo.books values (1184, 'MySQL Developer''s Library',      9325, 2009, '9780672329388', 650, 49.99); 
insert into a_bkinfo.books values (1301, 'ADO and Oracle Workbook',       9000, 2002, '0265615357',  0, 59.99); 
insert into a_bkinfo.books values (1302, 'ADO: the ebook',         9000, 2002, '0852515358', null, 49.99); 
insert into a_bkinfo.books values (1303, 'Rainbows and Rainbows',       9521, 2002, '0657895157', null, 59.99); 
insert into a_bkinfo.books values (1304, 'Stories of Discoveries',       9325, 2002, '0777788887', 300, 59.99); 
insert into a_bkinfo.books values (1305, 'Journeys Through Flatland',      9325, 1958, '0387515357', 100, 9.99); 
insert into a_bkinfo.books values (1306, 'Myths of SQL',         9664, 2000, '0454615027', 2895,259.99); 



insert into a_bkinfo.books values (1188, 'SQL for MySQL Developers',      9325, 2007, '9780314973851', 105, 49.99); 
insert into a_bkinfo.books values (1199, 'SQL is Fun',          null, 2007, null,   98, 19.99); 
insert into a_bkinfo.books values (2001, 'Programming SQL Server 2005',      9822, 2006, '0596003216', 675, 49.99); 
insert into a_bkinfo.books values (2002, 'SQL Server 2005 A Beginner''s Guide',    9030, 2006, '0072260939', 402, 39.99); 
insert into a_bkinfo.books values (2003, 'SQL Server 2005 Developer''s Guide',    9030, 2006, '0072260998', 402, 49.99); 
insert into a_bkinfo.books values (2004, 'SQL Server 2005 Stored Procedure Prg',   9030, 2006, '0072262888', 399, 59.99); 
insert into a_bkinfo.books values (2005, 'Developer''s Guide to SQL Server 2005',   9325, 2006, '0321382188', 894, 59.99); 
insert into a_bkinfo.books values (2006, 'T_SQL Programming (Inside series)',    9000, 2006, '9780756978', 390, 44.99); 
insert into a_bkinfo.books values (2007, 'T_SQL Querying (Inside series)',     9000, 2006, '9780733132', 391, 44.99); 
insert into a_bkinfo.books values (2008, 'SQL Server 2005 T_Sql Recipies',     9444, 2006, '159059570X', 503, 59.99); 
insert into a_bkinfo.books values (2009, 'SQL Server 2005 Express Edition',     9664, 2006, '0764589237', 150, 29.99); 



insert into a_bkinfo.books values (1258, '.Net Development for Microsoft Office',   9000, 2005, '0735621322', 500, 49.99); 
insert into a_bkinfo.books values (1689, 'Programming Visual Basic 2005: The Language',  9000, 2006, '9780735621831', 980, 59.99); 
insert into a_bkinfo.books values (1678, 'Pro .NET 2.0 Windows Forms and Controls VB 2005', 9444, 2006, '1590959693', 1002, 49.99); 
insert into a_bkinfo.books values (1278, 'Beginning VB 2008 Databases',      9444, 2008, '9781590599471', 408, 44.99); 
insert into a_bkinfo.books values (1478, 'Beginning OO Programming with VB 2005',   9444, 2006, '1590597695', 368, 44.99); 
insert into a_bkinfo.books values (1894, 'Programming Visual Basic 2005',     9822, 2005, '0596009496', 548, 39.99); 
insert into a_bkinfo.books values (1279, 'Data-Driven Services with Silverlight 2',   9822, 2009, '9780596523091', 336, 44.99); 
insert into a_bkinfo.books values (1776, 'Doing Objects in Visual Basic 2005',    9325, 2007, '9780321320490', 500, 49.99); 
insert into a_bkinfo.books values (1948, 'Framework Design Guidelines',      9325, 2006, '0321246756', 346, 44.99); 
insert into a_bkinfo.books values (1077, 'Programming for Poets',       9456, 2009, null,   401, 40.25); 
insert into a_bkinfo.books values (1835, 'Data Binding with Windows Forms 2.0',    9325, 2006, '032126892X', 634, 49.99); 
insert into a_bkinfo.books values (1541, 'Freethinkers: A History of American Secularism', 9023, 2004, '9780805077766', 448, 12.79); 
insert into a_bkinfo.books values (1542, 'The Great Agnostic: Robert Ingersoll and American Freethought', 
                          9021, 2013, '9780300137255', 256, 16.99); 
insert into a_bkinfo.books values (1543, 'Ties That Bind:The Story of an Afro-Cherokee Family in Slavery and Freedom', 
                          9024, 2006, '9780520250024', 327, 26.96); 
insert into a_bkinfo.books values (1544, 'The House on Diamond Hill: A Cherokee Plantation Story', 
                          9024, 2012, '9780807872673', 336, 17.76); 
insert into a_bkinfo.books values (1545, 'Team of Rivals: The Political Genius of Abraham Lincoln', 
                          9776, 2006, '9780739469767', 944, 13.96); 
insert into a_bkinfo.books values (1546, 'The Johnstown Flood',       9776, 1987, '9780671207144', 304, 10.39); 


insert into a_bkinfo.books values (1677, 'Windows Forms 2.0 Programming',     9325, 2006, '0321267966', 982, 74.99); 
insert into a_bkinfo.books values (1670, 'Applied .NET Framework Programming VB.NET',  9000, 2003, '0735678772', 608, 49.99); 
insert into a_bkinfo.books values (1401, 'Visual Studio Tools for Office',     9325, 2006, '0321334884', 976, 54.99); 
insert into a_bkinfo.books values (1537, 'The BedSide Book of Birds',      9725, 2005, '0385514832',  68, 29.95); 
insert into a_bkinfo.books values (1357, 'Why Birds Sing',         9725, 2005, '046507135X', 240, 26.00); 
insert into a_bkinfo.books values (1609, 'In the Company of Crows and Ravens',    9725, 2005, '0300100760', 376, 18.95); 
insert into a_bkinfo.books values (1979, 'Pro VB 2008 and the .NET 3.5 Platform',   9444, 2008, '9781590598221',1368, 59.99); 
insert into a_bkinfo.books values (1457, 'Visual Basic 2008 Recipes',      9444, 2008, '9781590599709', 300, 79.99); 
insert into a_bkinfo.books values (1425, 'The Singing Life of Birds',      9561, 2005, '0618405682', 468, 28.09); 
insert into a_bkinfo.books values (1978, 'Acoustic Communication in Birds Vol1',   9561, 1983, '9780124268012', 360,103.91); 


insert into a_bkinfo.books values (1621, 'The Unfeathered Bird',       9020, 2013, '9780691151342', 304, 31.29); 
insert into a_bkinfo.books values (1622, 'Bird Sense',          9020, 2012, '9780802779663', 265, 25.00); 
insert into a_bkinfo.books values (1623, 'Lichens of North America',      9021, 2001, '9780300082494', 828,135.00); 
insert into a_bkinfo.books values (1624, 'Outstanding Mosses and Liverworts of Pennsylvania and Nearby States',    
                          9021, 2006, '9780976092575',9, 19.99); 
insert into a_bkinfo.books values (1626, 'Bark: A Field Guide to Trees of the Northeast', 9021, 2011, '9781584658528', 280, 25.95); 
insert into a_bkinfo.books values (1625, 'Winter Weed Finder: A Guide to Dry Plants in Winter (Nature Study Guides)',    
                          9021, 1989, '9780912550176', 64, 4.95); 
insert into a_bkinfo.books values (1627, 'The Ants',          9022, 1990, '9780674040755', 732,120.18); 
insert into a_bkinfo.books values (1628, 'The Superorganism:The Beauty, Elegance, Strangeness of Insect Societies',    
                          9902, 2008, '9780393067040', 544, 34.65); 
insert into a_bkinfo.books values (1629, 'The Leafcutter Ants: Civilization by Instinct', 9022, 1990, '9780393338683', 160, 19.95); 
insert into a_bkinfo.books values (1630, 'The Social Conquest of Earth',     9022, 2012, '9780871404138', 352, 27.95); 



insert into a_bkinfo.books values (1448, 'Backyard Birdsong Guide: Western North America', 9561, 2008, '9780811863971',3192, 29.99); 
insert into a_bkinfo.books values (1877, 'High Performance MySQL',       9822, 2008, '9780596101718', 708, 49.99); 
insert into a_bkinfo.books values (1200, 'The Mismeasure of Man',       9902, 1996, '9780393314250', 488, 17.95); 
insert into a_bkinfo.books values (1245, 'A Scientific Approach to SQL Testing',   9902, 2010, '9780366214250', 488, 52.95); 
insert into a_bkinfo.books values (1774, 'Ever Since Darwin',        9902, 1992, '9780393308181', 288, 15.95); 
insert into a_bkinfo.books values (1234, 'Hen''s Teeth and Horse''s Toes ',     9902, 1994, '9780393311037', 416, 17.95); 
insert into a_bkinfo.books values (1269, 'Querying XML',         9745, 2006, '9781558607118', 848, 63.95); 
insert into a_bkinfo.books values (1525, 'Interface-Oriented Design',      9725, 2006, '0976697050', 213, 29.99); 
insert into a_bkinfo.books values (1619, 'The Oject-Oriented Thought Process',    9725, 2004, '9780672326110', 158, 29.99); 
insert into a_bkinfo.books values (1483, 'Programming with XML',       9745, 2008, null,   125, 19.99); 
insert into a_bkinfo.books values (2017, 'Functional Programming',       9528, 2010, '9781933988924', 528, 49.99); 

insert into a_bkinfo.books values (2018, 'Oracle Database 11g SQL',      9030, 2008, '9780071498500', 650, 49.99); 
insert into a_bkinfo.books values (2025, 'Oracle SQL Fundamentals I Exam Guide',   9030, 2008, '9780071597869', 572, 59.99); 
insert into a_bkinfo.books values (2027, 'Mastering Oracle SQL and SQL-Plus',    9444, 2005, '9781590594487', 464, 39.99); 

insert into a_bkinfo.books values (2028, 'Mastering Oracle Databases',      9444, 2010, '9781599594487', 464, 59.99); 
insert into a_bkinfo.books values (2029, 'The Forgotten Bird Strikes Back ',    9030, 2010, '9091599594487', 5, 1.99); 
insert into a_bkinfo.books values (2031, 'Comparative SQL',        9444, 2013, '9781599591237', 750, 99.99); 
insert into a_bkinfo.books values (2032, 'Oracle and the rest of the world',    9030, 2013, '9091599593217', 250, 55.99); 
insert into a_bkinfo.books values (2622, 'Outstanding Bryophytes',       9021, 2013, null,956, 89.99); 
insert into a_bkinfo.books values (2623, 'Hornworts and Liverworts in your Garden ',  9021, 2013, null,501, 29.99);

來源

2013-12-14 user3098749

您對發佈的SQL有什麼問題？我們可以幫助您解決哪些**具體問題？似乎缺少的唯一東西是處理NULL值page_counts的'else'或'IsNull'子句。 –

提供您想要查看的一些測試數據和結果！ –

我提供了更多數據。希望你能幫助我。 – user3098749

NULL需要處理。所以請使用IS NULL。
，爲您創造一個訂單定製範圍，你有做一個trick.The排序現在發生性格聰明 ..沒有編號明智。所以 50進入後450 ..

簡單的方法是使其固定格式..就像從'50' - >'050'追加'0'..你完成了。也通過LPAD'0使其3位數字。我爲您修改了查詢。！

SET @rownum:= 0; 
SELECT page_count, Ranking 
from(
SELECT CASE 
WHEN page_count BETWEEN 0 AND 49 OR page_count IS NULL THEN '000 - 049' 
WHEN page_count BETWEEN 50 AND 99 THEN '050 - 099' 
WHEN page_count BETWEEN 100 AND 149 THEN '100 - 149' 
WHEN page_count BETWEEN 150 AND 199 THEN '150 - 199' 
WHEN page_count BETWEEN 200 AND 249 THEN '200 - 249' 
WHEN page_count BETWEEN 250 AND 299 THEN '250 - 299' 
WHEN page_count BETWEEN 300 AND 349 THEN '300 - 349' 
WHEN page_count BETWEEN 350 AND 399 THEN '350 - 399' 
WHEN page_count BETWEEN 400 AND 449 THEN '400 - 449' 
WHEN page_count BETWEEN 450 AND 499 THEN '450 - 499' 
WHEN page_count BETWEEN 500 AND 549 THEN '500 - 549' 
WHEN page_count BETWEEN 550 AND 599 THEN '550 - 599' 
WHEN page_count BETWEEN 600 AND 649 THEN '600 - 649' 
WHEN page_count >=650 THEN 'Page Count over 650' 
END AS page_count 
, 
    @rownum:= @rownum + 1 AS Ranking 
    FROM books 
)tbl 
    GROUP BY page_count;

來源

2013-12-15 00:03:14

有人可以幫助我通過別名和處理空值組嗎？

回答

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