循環兩個日期以獲取值

Question

我有一個表格，當值更改時保存條目，但是現在我需要獲取兩個日期之間每天的值。

所以在數據庫中，我有以下幾點：

2015-10-17 25 
2015-10-12 20 
2015-10-01 5 

我需要的是得到的值整月

2015-10-01 5 
2015-10-02 5 
.... 
2015-10-12 20 
2015-10-13 20 

我將如何實現這一目標？我有下面的代碼

http://www.sqlfiddle.com/#!2/ca447e/1/0

CREATE PROCEDURE sp_GetMonthVals(IN StartDate DATETIME, IN EndDate DATETIME) 
BEGIN 
    DECLARE CurrentDate DATETIME; 
    SET @CurrentDate = StartDate; 

    label1: WHILE @CurrentDate < @EndDate DO 
     SELECT @CurrentDate, DVal FROM Table1 WHERE MDate <= @CurrentDate ORDER BY MDate DESC LIMIT 1; 
     SET @CurrentDate = DATE_ADD(CurrentDate, INTERVAL 1 DAY); 
    END WHILE label1; 
END; 



CREATE TABLE Table1 
    (`id` int, `MDate` varchar(10), `DVal` int) 
; 

INSERT INTO Table1 
    (`id`, `MDate`, `DVal`) 
VALUES 
    (1, '2015-10-17', 25), 
    (2, '2015-10-12', 20), 
    (3, '2015-10-01', 5) 
; 
CALL sp_GetMonthVals('2015-10-01', '2015-10-31'); 

Answer 1

我已成功地做到這一點使用下面的，如果任何人都可以提高查詢的話，我會接受他們的回答

DROP PROCEDURE IF EXISTS sp_GetMonthVals; 
DELIMITER // 
CREATE PROCEDURE sp_GetMonthVals(IN StartDate DATETIME, IN EndDate DATETIME) 
BEGIN 

    DECLARE CurrentDate DATETIME; 
    SET @CurrentDate = StartDate; 

    DROP TABLE IF EXISTS _tmpMonthVals; 
    CREATE TABLE _tmpMonthVals (`MDate` DATETIME, `DVal` int); 

    label1: WHILE @CurrentDate < EndDate DO 
     INSERT INTO _tmpMonthVals SELECT @CurrentDate, DVal FROM Table1 WHERE MDate <= @CurrentDate ORDER BY MDate DESC LIMIT 1; 
     SET @CurrentDate = DATE_ADD(@CurrentDate, INTERVAL 1 DAY); 
    END WHILE label1; 
    SELECT * FROM _tmpMonthVals; 
END// 
DELIMITER ; 

CREATE TABLE IF NOT EXISTS Table1 
    (`id` int, `MDate` DATETIME, `DVal` int) 
; 

INSERT INTO Table1 
    (`id`, `MDate`, `DVal`) 
VALUES 
    (1, '2015-10-17', 25), 
    (2, '2015-10-12', 20), 
    (3, '2015-10-01', 5); 

CALL sp_GetMonthVals('2015-10-01', '2015-10-31');