Mysql到Informix的查詢

Question

我用下面的查詢從mysql表中檢索信息。

SELECT YEARWEEK(fecha,2) ,CONCAT('Semana ', WEEK(fecha)) as y,count(*) as a 
FROM mobile09 
WHERE fecha BETWEEN TODAY - 30 AND TODAY GROUP BY 1 ORDER BY 1 ASC 

如何在具有相同表的Informix數據庫中獲得相同的結果？

Answer 1

您將不得不爲Informix實現自己的一週功能。

幸運的是，這已經在做：IBM Developerworks

CREATE FUNCTION day_one_week_one(yyyy INTEGER) 
    RETURNING DATE 
    WITH(NOT VARIANT) 
    DEFINE jan1 DATE; 
    LET jan1 = MDY(1, 1, yyyy); 
    RETURN jan1 + MOD(11 - WEEKDAY(jan1), 7) - 3; 
END FUNCTION; 

CREATE FUNCTION iso8601_weeknum(dateval DATE DEFAULT TODAY) 
RETURNING CHAR(2) 
WITH(NOT VARIANT) 
    DEFINE rv CHAR(8); 
    DEFINE yyyy CHAR(4); 
    DEFINE ww CHAR(2); 
    DEFINE d1w1 DATE; 
    DEFINE tv DATE; 
    DEFINE wn INTEGER; 
    DEFINE yn INTEGER; 
    -- Calculate year and week number. 
    LET yn = YEAR(dateval); 
    LET d1w1 = day_one_week_one(yn); 
    IF dateval < d1w1 THEN 
     -- Date is in early January and is in last week of prior year 
     LET yn = yn - 1; 
     LET d1w1 = day_one_week_one(yn); 
    ELSE 
     LET tv = day_one_week_one(yn + 1); 
     IF dateval >= tv THEN 
      -- Date is in late December and is in the first week of next year 
      LET yn = yn + 1; 
      LET d1w1 = tv; 
     END IF; 
    END IF; 
    LET wn = TRUNC((dateval - d1w1)/7) + 1; 
    -- Calculation complete: yn is year number and wn is week number. 
    -- Format result. 
    LET yyyy = yn; 
    IF wn < 10 THEN 
     LET ww = "0" || wn; 
    ELSE 
     LET ww = wn; 
    END IF 

    RETURN ww; 
END FUNCTION; 

現在，你應該能夠做到

select 
    year(fecha) || iso8601_weeknum(fecha), 
    'Semana ' || iso8601_weeknum(fecha) as y, 
    count(*) as a 
from 
    mobile09 
where 
    fecha between today - 30 and today 
group by 
    1, 2 
order by 
    1 asc;