從postgres中的同一查詢中提取出「水平」列中的「年份」列和「顯示年份」列sql

Question

我有這個查詢可以爲我返回正確的結果。

SELECT distinct(companies.name), 
       date_part('year', scopes.time_stamp) as fy, 
       count(def.dp_code)as answ_count  
FROM companies companies, 
    scopes scopes, 
    values dp, 
    definition def, 
    content cd 
where scopes.company_id = companies.company_id 
    and scopes.scope_id=dp.scope_id 
    and dp.content_id=cd.definition_id 
    and def.definition_id=cd.definition_id 
group by companies.name, date_part('year',scopes.time_stamp) 
ORDER BY companies.name 

以下是上述查詢的結果。

name   fy   count 

3M Co  2002 200 
3M Co  2003 100 
3M Co  2004 150 
3M Co  2005 160 
3M Co  2006 169 
AB SKF  2002 212 
AB SKF  2003 214 
AB SKF  2004 215 
AB SKF  2005 237 
AB SKF  2006 456 
3i Group plc 2002 546 
3i Group plc 2003 214 
3i Group plc 2004 215 
3i Group plc 2005 237 
3i Group plc 2006 456 

我需要水平顯示的結果是這樣的：

name   2002 2003 2004 2005 2006 
3M Co  200 100 150 160 169 
AB SKF   
3i Group plc 546 214 215 237 456 

修改後的查詢，但我沒有得到正確的count.I不知道如何計算ans_count.Please幫我這一點。

SELECT 
    distinct(companies.name), 
    count(CASE WHEN date_part('year', scopes.time_stamp) = 2002 THEN answ_count end) AS Year1, 
    count(CASE WHEN date_part('year', scopes.time_stamp) = 2003 THEN answ_count end) AS Year2, 
    count(CASE WHEN date_part('year', scopes.time_stamp) = 2004 THEN answ_count end) AS Year3, 
    count(CASE WHEN date_part('year', scopes.time_stamp) = 2005 THEN answ_count end) AS Year4, 
    count(CASE WHEN date_part('year', scopes.time_stamp) = 2006 THEN answ_count end) AS Year5, 
    count(CASE WHEN date_part('year',scopes.time_stamp) = 2007 THEN answ_count end) AS Year6, 
    count(CASE WHEN date_part('year', scopes.time_stamp) = 2008 THEN answ_count end) AS Year7, 
    count(CASE WHEN date_part('year', scopes.time_stamp) = 2009 THEN answ_count end) AS Year8, 
    count(CASE WHEN date_part('year', scopes.time_stamp) = 2010 THEN answ_count end) AS Year9, 
    count(CASE WHEN date_part('year', scopes.time_stamp) = 2011 THEN answ_count end) AS Year10, 
    count(CASE WHEN date_part('year', scopes.time_stamp) = 2012 THEN answ_count end) AS Year11, 
    count(CASE WHEN date_part('year', scopes.time_stamp) = 2013 THEN answ_count end) AS Year12, 
    count(CASE WHEN date_part('year', scopes.time_stamp) = 2014 THEN answ_count end) AS Year13, 
    count(CASE WHEN date_part('year', scopes.time_stamp) = 2015 THEN answ_count end) AS Year14, 
    count(CASE WHEN date_part('year', scopes.time_stamp) = 2016 THEN answ_count end) AS Year16 
    FROM 
    companies companies,value_scopes value_scopes,dp_values dp,dp_definition def,dp_content_definition cd 
    where 
    value_scopes.company_id = companies.company_id 
    and value_scopes.value_scope_id=dp.value_scope_id 
    and dp.dp_content_definition_id=cd.dp_content_definition_id 
    and def.dp_definition_id=cd.dp_definition_id 
    and value_scopes.is_partial='f' 
    group by companies.name 
    ORDER BY companies.name; 

Answer 1

現代，明確JOIN的，今年的東西在派生表：

select name, 
     count(case when year = 2002 then 1 end) as Year2002, 
     count(case when year = 2003 then 1 end) as Year2003, 
     ... 
     count(case when year = 2016 then 1 end) as Year2016 
FROM 
(
    SELECT companies.name, 
      date_part('year', scopes.time_stamp) AS Year 
    FROM companies companies 
    JOIN value_scopes value_scopes ON value_scopes.company_id = companies.company_id 
    JOIN dp_values dp ON value_scopes.value_scope_id = dp.value_scope_id 
    JOIN dp_content_definition cd ON dp.dp_content_definition_id = cd.dp_content_definition_id 
    JOIN dp_definition def ON def.dp_definition_id=cd.dp_definition_id 
    WHERE value_scopes.is_partial = 'f' 
) dt 
group by name 
ORDER BY name