Sql server database store procedure query - sql-server-2017

Question

I have two tables as below:
1) UserFavouriteCurrencies
CREATE TABLE [dbo].[UserFavouriteCurrencies](
[Id] [bigint] IDENTITY(1,1) NOT NULL,
[UserId] [int] NULL,
[CurrencyId] [int] NULL,
[EntryDate] [datetime] NULL,
CONSTRAINT [PK_UserFavouriteCurrencies] PRIMARY KEY CLUSTERED
(
[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
Above table is holding data of user favorite companies
2) CurrencyRates
CREATE TABLE [dbo].[CurrencyRates](
[Id] [bigint] IDENTITY(1,1) NOT NULL,
[CurrencyId] [int] NULL,
[Price] [float] NULL,
[Open_24h] [float] NULL,
[Volume_24h] [float] NULL,
[Low_24h] [float] NULL,
[High_24h] [float] NULL,
[Volume_30d] [float] NULL,
[BestBid] [float] NULL,
[BestAsk] [float] NULL,
[TradeId] [bigint] NULL,
[PriceDate] [datetime] NULL,
[PriceDateTimestamp] [bigint] NULL,
[OpenInterest] [float] NULL,
CONSTRAINT [PK_CoinbaseTickerRatesMaster] PRIMARY KEY CLUSTERED
(
[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
Above table holds rates details of currencies.
Call : EXEC sp_Getdata 1(Here 1 in UserId of UserFavouriteCurrencies table)
I need all records for particular currencies last latest records in one query as below
DECLARE #Today DATETIME = GETDATE(), #PrevDate DATETIME = GETDATE()<br>
SELECT TOP 1 Price, PriceDate, Volume_24h, PriceDateTimestamp
FROM CurrencyRates
WHERE CurrencyId = #CurrencyId AND PriceDate <= #Today
ORDER BY PriceDateTimestamp DESC
Above query is only select data for one particular currency but I need the data related to user which added on UserFavouriteCurrencies table.
Please help me to write store procedure for this query
Thanks in advance.

Answer 1

For each currency in UserFavouriteCurrencies Table, consider the query below
SELECT
uc.Id -- This is the userId
,cr.Price
,cr.PriceDate,
,cr.Volume_24h
,cr.PriceDateTimestamp
FROM
UserFavouriteCurrencies AS uc
INNER JOIN CurrencyRates AS cr -- See Hints : 1
ON cr.CurrencyId = uc.CurrencyId
WHERE
PriceDate <= GETDATE()
AND
uc.Id = #Id
-- You can add other Predicates Here...
Hints:
Consider using LEFT OUTER JOIN if user's currency may not exist in CurrencyRates
!This will however introduce NULLs which you must handle