SQL Query help needed - Multiple rows in 1st table should match to multiple table in 2nd table - sql

Question

Problem Illustration
I am trying to find that magical query to generate summary information. I have mapped my problem into fictitious illustration. I have 'WaterLeakage%' table which records leakage occurred in hotel rooms over several year.
I have another table which records WaterConsumption in liters for each table.
Now i have to find actual water leakage in liters for given room number over given date range.
Basically i have to group several rows in 'WaterLeakage%' table to several rows in 'WaterConsumption' table. I am trying to figure out magical efficient query to find this. Unable to find it, please help.

Answer 1

DECLARE #START_DATE_PARAM DATE = '01/10/2017';
DECLARE #END_DATE_PARAM DATE = '01/31/2017';
DECLARE #ROOM_NUMBER INT = 101;
IF (EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = '#WATER_CONSUMPTION'))
DROP TABLE #WATER_CONSUMPTION;
IF (EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = '#WATER_LEAKAGE_PER'))
DROP TABLE #WATER_LEAKAGE_PER;
--Table for daily daily water consumption per room
CREATE TABLE #WATER_CONSUMPTION(
ROOM_NUMBER INT,
UDAY DATE,
WATER_CONSUMPTION_LITER INT
)
--Table for water leakage percent per room for date range
CREATE TABLE #WATER_LEAKAGE_PER
(
ROOM_NUMBER INT,
START_DATE DATE,
END_DATE DATE,
WATER_LEAKAGE_PERCENT INT
)
-- Raw Data
INSERT INTO #WATER_LEAKAGE_PER(ROOM_NUMBER,START_DATE,END_DATE,WATER_LEAKAGE_PERCENT)
VALUES(101,'2017/01/01','2017/01/02',5),
(102,'2017/01/01','2017/01/05',10),
(101,'2017/01/04','2017/02/06',10);
-- Raw Data
INSERT INTO #WATER_CONSUMPTION
VALUES(101,'2017/01/01',100),
(101,'2017/01/02',100),
(101,'2017/01/03',100),
(101,'2017/01/04',100),
(101,'2017/01/05',100),
(101,'2017/01/06',100),
(102,'2017/01/01',100),
(102,'2017/01/02',100),
(102,'2017/01/03',100),
(102,'2017/01/04',100),
(102,'2017/01/05',100);
DECLARE #TotalLeak REAL = 0;
SELECT * FROM #WATER_CONSUMPTION;
SELECT * FROM #WATER_LEAKAGE_PER;
SELECT * FROM #WATER_CONSUMPTION T1 JOIN (SELECT * FROM #WATER_LEAKAGE_PER WHERE ROOM_NUMBER=#ROOM_NUMBER) T2
ON (T1.ROOM_NUMBER=T2.ROOM_NUMBER AND T1.UDAY >= T2.START_DATE AND T1.UDAY <= T2.END_DATE);
DROP TABLE #WATER_CONSUMPTION;
DROP TABLE #WATER_LEAKAGE_PER;
I am very close to solution now. Basically i changed my thinking. I will join reverse now.

Answer 2

BEGIN
--Input Parameters for calculating water wastage between date range
DECLARE #START_DATE_PARAM DATE = '01/10/2017';
DECLARE #END_DATE_PARAM DATE = '01/31/2017';
--Table for daily daily water consumption per room
CREATE TABLE #WATER_CONSUMPTION(
ROOM_NUMBER INT,
UDAY DATE,
WATER_CONSUMPTION_LITER INT
)
--Table for water leakage percent per room for date range
CREATE TABLE #WATER_LEAKAGE_PER
(
ROOM_NUMBER INT,
START_DATE DATE,
END_DATE DATE,
WATER_LEAKAGE_PERCENT INT,
LEAKAGE_PER_DAY_IN_LITER INT
)
-- Leakage in liter per room for each day, This will have multiple entries for room and date if room number and date is available in multiple date ranges, ex. in #WATER_CONSUMPTION table for room number 101 we have multiple entries with overlapping dates
CREATE TABLE #DAY_WISE_LEAKAGE
(
ROOM_NUMBER INT,
LDATE DATE,
LEAKAGE_IN_LITER INT
)
-- Raw Data
INSERT INTO #WATER_LEAKAGE_PER(ROOM_NUMBER,START_DATE,END_DATE,WATER_LEAKAGE_PERCENT)
VALUES(101,'2017/01/15','2017/01/18',30),
(102,'2017/01/15','2017/01/18',10),
(101,'2017/01/15','2017/02/13',5);
-- Raw Data
INSERT INTO #WATER_CONSUMPTION
VALUES(101,'01/01/2017',1001),
(101,'01/02/2017',1001),
(101,'01/03/2017',1001),
(101,'01/04/2017',1001),
(101,'01/05/2017',1001),
(101,'01/06/2017',1001),
(101,'01/07/2017',1001),
(101,'01/08/2017',1001),
(101,'01/09/2017',1001),
(101,'01/10/2017',1001),
(101,'01/11/2017',1001),
(101,'01/12/2017',1001),
(101,'01/13/2017',1001),
(101,'01/14/2017',1001),
(101,'01/15/2017',1001),
(101,'01/16/2017',1001),
(101,'01/17/2017',1001),
(101,'01/18/2017',1001),
(101,'01/19/2017',1001),
(101,'01/20/2017',1001),
(101,'01/21/2017',1001),
(101,'01/22/2017',1001),
(101,'01/23/2017',1001),
(101,'01/24/2017',1001),
(101,'01/25/2017',1001),
(101,'01/26/2017',1001),
(101,'01/27/2017',1001),
(101,'01/28/2017',1001),
(101,'01/29/2017',1001),
(101,'01/30/2017',1001),
(101,'01/31/2017',1001);
DECLARE #ROOM_NUMBER INT
DECLARE #START_DATE DATE
DECLARE #END_DATE DATE
DECLARE #WATER_LEAKAGE_PERCENT INT
-- cursor for calculating water wastage pre date range per day available in #WATER_LEAKAGE_PER table
DECLARE WATER_LEAKAGE_PER_CURSOR CURSOR FOR
SELECT ROOM_NUMBER,START_DATE,END_DATE,WATER_LEAKAGE_PERCENT FROM #WATER_LEAKAGE_PER
OPEN WATER_LEAKAGE_PER_CURSOR
FETCH NEXT FROM WATER_LEAKAGE_PER_CURSOR
INTO #ROOM_NUMBER, #START_DATE ,#END_DATE, #WATER_LEAKAGE_PERCENT
WHILE ##FETCH_STATUS = 0
BEGIN
DECLARE #TOTAL_WATER_USED_FOR_DATE_RANGE INT=0;
DECLARE #NUMBER_OF_DAYS INT=0;
DECLARE #LEAKAGE_PER_DAY_IN_LITER INT=0;
-- Total Liters of water used for 1 date range
SELECT #TOTAL_WATER_USED_FOR_DATE_RANGE =SUM(WATER_CONSUMPTION_LITER),#NUMBER_OF_DAYS=COUNT(1) FROM #WATER_CONSUMPTION WHERE ROOM_NUMBER=#ROOM_NUMBER AND UDAY BETWEEN #START_DATE AND #END_DATE;
-- Liters of water leakage per day for selevted date range in cursor
SELECT #LEAKAGE_PER_DAY_IN_LITER=((#TOTAL_WATER_USED_FOR_DATE_RANGE*#WATER_LEAKAGE_PERCENT)/100)/#NUMBER_OF_DAYS;
UPDATE #WATER_LEAKAGE_PER SET LEAKAGE_PER_DAY_IN_LITER = #LEAKAGE_PER_DAY_IN_LITER WHERE ROOM_NUMBER=#ROOM_NUMBER AND START_DATE = #START_DATE AND END_DATE=#END_DATE AND WATER_LEAKAGE_PERCENT=#WATER_LEAKAGE_PERCENT;
-- generate dates and water leakage, this will be used for actual calculation of water leakage in date range.
;WITH n AS
(
SELECT TOP (DATEDIFF(DAY, #START_DATE, #END_DATE) + 1)
n = ROW_NUMBER() OVER (ORDER BY [object_id])
FROM sys.all_objects
)
INSERT INTO #DAY_WISE_LEAKAGE SELECT #ROOM_NUMBER, DATEADD(DAY, n-1, #START_DATE),#LEAKAGE_PER_DAY_IN_LITER
FROM n;
FETCH NEXT FROM WATER_LEAKAGE_PER_CURSOR
INTO #ROOM_NUMBER, #START_DATE ,#END_DATE, #WATER_LEAKAGE_PERCENT
END
CLOSE WATER_LEAKAGE_PER_CURSOR;
DEALLOCATE WATER_LEAKAGE_PER_CURSOR;
-- Average of Liters of water leakage per Room number.
SELECT ROOM_NUMBER,SUM(LEAKAGE_IN_LITER) FROM #DAY_WISE_LEAKAGE WHERE LDATE BETWEEN #START_DATE_PARAM AND #END_DATE_PARAM GROUP BY ROOM_NUMBER;
DROP TABLE #WATER_CONSUMPTION;
DROP TABLE #WATER_LEAKAGE_PER;
DROP TABLE #DAY_WISE_LEAKAGE
END