从日期中提取一列中的所有月份

Question

我的表 Kot_items 中有一个日期字段。如果数据库中不存在月份，如何提取所有月份名称？

select  distinct month(Tran_date) as mon
from Kot_items

数据库中的数据

MON  monthname
    1          jan
    2          feb
    3          mar

异常结果

MON  monthname
1       jan
2       feb
3       mar
4       Apr
5       mar
6       june
7       july
8       Aug
9       Sep
10      Oct
11      nov
12      Dec

更新帖子::

形成这个查询::

选择年份(tran_date) 作为年份编号， QUARTER(tran_date) 作为季数， 月（tran_date）作为星期一 来自 KOT_Items

yearnumber  quarternumber   mon 
2014    2           4   
2014    2           4   
2014    2           4   
2014    2           4   
2014    2           4   
2014    2           4   
2014    2           4   
2014    2           4   
2014    2           4   
2014    2           4   
2014    2           4   
2014    2           4   
2014    2           4   

喜欢的结果除外

yearnumber  quarternumber   mon 
2014    1           1   
2014    1           2   
2014    1           3   
2014    2           3   
2014    2           4   
2014    2           5   
2014    3           6   
2014    3           7   
2014    3           8   
2014    4                9  
2014    4           10  
2014    4           11  
2014    4           12

Answer 1

一种方法是创建一个包含所有月份的表。然后，您可以在此表和您的事务表之间使用外连接。

CREATE TABLE months (mon INT, monthname CHAR(3)) AS
SELECT 1, 'Jan'
UNION
SELECT 2, 'Feb'
UNION
SELECT 3, 'Mar'
...
SELECT 12, 'Dec'

如果你不能这样做，你可以使用 UNION 子查询：

SELECT * FROM (
    SELECT 1 AS mon, 'Jan' AS monthname
    UNION
    SELECT 2, 'Feb'
    UNION
    SELECT 3, 'Mar'
    ...
    SELECT 12, 'Dec') AS months
LEFT JOIN Kot_items AS i ON months.mon = MONTH(i.tran_date)

然后可以将其与您的事务表连接。

对于年份、季度和月份，请执行以下操作：

SELECT YEAR(NOW()) AS yearnumber, 1 as quarternumber, 1 as mon
UNION ALL
SELECT YEAR(NOW()), 1, 2
UNION ALL
SELECT YEAR(NOW()), 1, 3
UNION ALL
SELECT YEAR(NOW()), 2, 4
UNION ALL
SELECT YEAR(NOW()), 2, 5
UNION ALL
SELECT YEAR(NOW()), 2, 6
UNION ALL
SELECT YEAR(NOW()), 3, 7
UNION ALL
SELECT YEAR(NOW()), 3, 8
UNION ALL
SELECT YEAR(NOW()), 3, 9
UNION ALL
SELECT YEAR(NOW()), 4, 10
UNION ALL
SELECT YEAR(NOW()), 4, 11
UNION ALL
SELECT YEAR(NOW()), 4, 12

如果您使用我上面显示的months 表，您可以简单地将quarternumber 列添加到表中。要制作当前年份的表格，您可以使用如下查询：

SELECT YEAR(NOW()), quarternumber, mon
FROM months

Answer 2

试试SELECT MONTHNAME(datefield) as monthname FROM tablename

Answer 3

SELECT m.mon, m.month
FROM (
SELECT 1 as mon, 'Jan' as month
UNION    
SELECT 2 as mon, 'Feb' as month
UNION    
SELECT 1 as mon, 'Mar' as month
UNION    
SELECT 1 as mon, 'Apr' as month
UNION    
SELECT 1 as mon, 'May' as month
UNION    
SELECT 1 as mon, 'Jun' as month
UNION    
SELECT 1 as mon, 'Jul' as month
UNION    
SELECT 1 as mon, 'Aug' as month
UNION    
SELECT 1 as mon, 'Sep' as month
UNION    
SELECT 1 as mon, 'Oct' as month
UNION    
SELECT 1 as mon, 'Nov' as month
UNION    
SELECT 1 as mon, 'Dec' as month  
) AS m
LEFT JOIN Kot_items k ON m.month = k.month(Tran_date)

Answer 4

你可以使用：

SELECT MONTH(Trans_date) as mon, MONTHNAME(Tran_date) as monthname FROM Kot_items ;

From here

所有月份

SELECT 1 as mon, 'January' AS
    MONTH
    UNION SELECT 2 as mon 'February' AS
    MONTH
    UNION SELECT 3 as mon 'March' AS
    MONTH
    UNION SELECT 4 as mon 'April' AS
    MONTH
    UNION SELECT 5 as mon 'May' AS
    MONTH
    UNION SELECT 6 as mon 'June' AS
    MONTH
    UNION SELECT 7 as mon 'July' AS
    MONTH
    UNION SELECT 8 as mon 'August' AS
    MONTH
    UNION SELECT 9 as mon 'September' AS
    MONTH
    UNION SELECT 10 as mon 'October' AS
    MONTH
    UNION SELECT 11 as mon 'November' AS
    MONTH
    UNION SELECT 12 as mon 'December' AS
    MONTH
    ) AS m

最简单的方法是创建一个单独的表，并加入您当前拥有的表 (Kot_items) From here