用三个表连接sql查询

Question

I have to join three tables.

1 table is transaction , next table is shops, 3rd is weather.

I want to fetch data from all of these three ,but in case of weather table > id,tamp_c,datetime column name .

The query is:-

 select HOUR(transaction.time) as Hour ,
        TRUNCATE(sum(transaction.total),2) as Total_Sales,
        shops.gstIncludedSales as GST_Inc_Sales,
        shops.gstFreeSales as GST_Free,weather.temp_c 
        from transaction,shops,weather 
        where transaction.shopid=shops.id and transaction.shopid=7
        and transaction.transaction_date ='2015-05-25' 
        group by hour 
        ORDER BY hour DESC

The problem is that I want to apply a where clause with weather.datetime table separation for particular date like time(datetime)='2015-05-25' , but it's not working.

Answer 1

Try this:

WHERE transaction.transaction_date >= '2015-05-25' AND transaction.transaction_date < '2015-05-26'

That will return rows with timestamp during the whole day (midnight until midnight - time is implied).

If you have SQLServer 2014 you canm use DATE(transaction.transaction_date).

Answer 2

Does this do what you want

SELECT HOUR(transaction.time) as Hour ,
   TRUNCATE(sum(transaction.total),2) as Total_Sales,
   shops.gstIncludedSales as GST_Inc_Sales,
   shops.gstFreeSales as GST_Free,weather.temp_c 
FROM transaction
JOIN shops ON transaction.shopid=shops.id
JOIN weather ON DATE(transaction.transaction_date) = DATE(weather.datetime)
WHERE DATE(transaction.transaction_date)='2015-05-25' AND transaction.shopid=7
GROUP by hour 
ORDER BY hour DESC

(Assuming you are using MySQL)