如何通過前面日期連接兩個表和行僅

Question

我有兩個表

-- 
-- Table structure for table `d_statistics_report_temp` 
-- 

CREATE TABLE IF NOT EXISTS `d_statistics_report_temp` (
    `srt_id` int(10) NOT NULL AUTO_INCREMENT , 
    `pub_name` varchar(100) DEFAULT NULL , 
    `sal_must_pay_date` date DEFAULT NULL , 
    `total_sales` float(7,0) DEFAULT NULL, 
    `total_must_pay` float(7,0) NOT NULL, 
    `pub_share` float(7,0) DEFAULT NULL , 
    `pub_id` int(11) DEFAULT NULL COMMENT , 
    `conversion_doc` varchar(255) NOT NULL, 
    PRIMARY KEY (`srt_id`) 
) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=6 ; 

-- 
-- Dumping data for table `d_statistics_report_temp` 
-- 

INSERT INTO `d_statistics_report_temp` 
(`srt_id`, `pub_name`, `sal_must_pay_date`, `total_sales`, `total_must_pay`, `pub_share`, `pub_id`, `conversion_doc`) 
VALUES 
(1, 'sara', '2013-03-01', 50, 0, 15, 256, ''), 
(2, 'sara', '2013-04-01', 20, 0, 15, 256, ''), 
(3, 'sara', '2013-05-01', 80, 0, 15, 256, ''), 
(4, 'sara', '2013-06-01', 10, 0, 15, 256, ''), 
(5, 'sara', '2013-07-01', 20, 0, 15, 256, ''), 
(6, 'sara', '2013-08-01', 70, 0, 15, 256, ''), 
(7, 'sara', '2013-09-01', 90, 0, 15, 256, ''), 
(8, 'adam', '2013-05-01', 10, 0, 15, 255, '') 

，第二個表

-- 
-- Table structure for table `d_statistics_docs` 
-- 

CREATE TABLE IF NOT EXISTS `d_statistics_docs` (
    `sd_id` int(11) NOT NULL AUTO_INCREMENT, 
    `sd_pub` int(11) NOT NULL, 
    `sd_date` date NOT NULL, 
    `sd_doc` text NOT NULL, 
    `price` int(11) NOT NULL, 
    PRIMARY KEY (`sd_id`) 
) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=16 ; 

-- 
-- Dumping data for table `d_statistics_docs` 
-- 

INSERT INTO `d_statistics_docs` (`sd_id`, `sd_pub`, `sd_date`, `sd_doc`, `price`) VALUES 

(9, 256, '2013-03-01', 'scifiwallpaper1.jpg'), 
(10, 256, '2013-04-01', 'scifiwallpaper1.jpg'), 
(11, 256, '2013-05-01', ''), 
(12, 256, '2013-06-01', 'scifiwallpaper1.jpg'), 
(13, 256, '2013-07-01', ''), 
(14, 256, '2013-08-01', ''), 
(15, 256, '2013-09-01', 'scifiwallpaper1.jpg'); 

我想加入表來獲得total_sales每一個pub_id（PUBLISHER_ID ）每sd_date

但我想把條件​​得到total_sales爲此sd_date只有

如果sd_doc NOT NULL本月回報total_sales和所有個月前繼

輸出例如

9 256  2013-03-01 scifiwallpaper1.jpg 50 

10 256  2013-04-01 scifiwallpaper1.jpg 20 

11 256  2013-05-01   NULL   80 

12 256 2013-06-01 scifiwallpaper1.jpg 90 // total 10 + 80 

13 256  2013-07-01   NULL   20 

14 256  2013-08-01   NULL  70 

15 256  2013-09-01 scifiwallpaper1.jpg 180 // total of 90+70+20 

* 注：sal_must_pay_date = sd_date在第二個表*

Answer 1

你可以使用變量來跟蹤以前的行（只要您正確訂購）。

SET @i = 0.0; 

SELECT rt.srt_id, 
     rt.pub_id, 
     d.sd_date, 
     CASE WHEN d.sd_doc != '' THEN d.sd_doc END sd_doc, 
     rt.total_sales, 
     @i + rt.total_sales AS Cumulative_Total, 
     @i:= CASE WHEN d.sd_doc = '' THEN @i + rt.total_sales ELSE 0 END AS Increment 
FROM d_statistics_report_temp rt 
     INNER JOIN d_statistics_docs d 
      ON rt.pub_id = d.sd_pub 
      AND rt.sal_must_pay_date = d.sd_date 
ORDER BY rt.pub_id, d.sd_date; 

在這種情況下，每行的變量@i塗改，重置爲0，如果sd_doc不爲空，或添加到其前面的少量如果sd_doc爲空：那麼如下您的查詢可以寫。

Example on SQL Fiddle