I've got a Snowflake SQL query I'm trying to execute in R via ODBC connection that looks like this
SET quiet=TRUE;
USE SOMEDATABASE.SOMESCHEMA;
--Select timestamp of last sale per customer
DROP TABLE IF EXISTS sales;
CREATE TEMPORARY TABLE sales(CustomerId VARCHAR(16777216), SaleTS TIMESTAMP_NTZ(9));
INSERT INTO sales
SELECT CustomerId,
SaleTS
FROM SALES
WHERE SaleTS>= '2020-11-19 00:00:00'
AND SaleTS <= '2020-11-19 23:59:59.999'
GROUP BY CustomerId;
--Use temp table to get correct row from sales table
SELECT SUM(SalesDetail.price) as SumPrice
COUNT(*) as SoldVolume
FROM sales
LEFT JOIN SALES as SalesDetail
ON Sales.CustomerId = SalesDetail.CustomerId
AND sales.SaleTS = SalesDetail.SaleTS
Querying Microsoft SQL Server from R I'd normally include set nocount no;
at the top of the query to ensure only the last step is returned to R to avoid the error Actual statement count 6 did not match the desired statement count 1.
Error makes sense, SQL is returning 6 components when R is expecting 1 (6 one for each step in my SQL query). In Snowflake there doesn't appear to be an option to set nocount on in the same way. My question is how do I avoid the above error. Does anyone have any experience of executing a mutli-step Snowflake SQL query via R? How can I get R to receive just the last statement from the ODBC connection. So far I've tried set nocount=TRUE;
, set echo=FALSE;
, set message=FALSE;
, SET quiet=TRUE
etc
Snowflake SQL is expressive enough and proposed code could be structured as single query:
WITH cte AS (
SELECT CustomerId, MAX(SaleTS) AS SaleTS -- here agg function is required
FROM SALES
WHERE SaleTS>= '2020-11-19 00:00:00'
AND SaleTS <= '2020-11-19 23:59:59.999'
GROUP BY CustomerId
)
SELECT SUM(SalesDetail.price) as SumPrice
COUNT(*) as SoldVolume
FROM cte
LEFT JOIN SALES as SalesDetail
ON Sales.CustomerId = SalesDetail.CustomerId
AND sales.SaleTS = SalesDetail.SaleTS;
The original query is using the same name for both table and temporary table differing only by case sales
vs SALES
, which is error-prone.
Second: database and schema could be set up during establishing connection, so there is no need for USE
inside script. Alternatively fully qualified name could be used in the script.
I guess the intent of query is as follow:
WITH cte AS (
SELECT *
FROM SOMEDATABASE.SOMESCHEMA.SALES
WHERE SaleTS BETWEEN '2020-11-19 00:00:00' AND '2020-11-19 23:59:59.999'
QUALIFY ROW_NUMBER() OVER(PARTITION BY CustomerId ORDER BY SaleTS DESC) = 1
)
SELECT COUNT(*) AS SoldVolume, SUM(price) as SumPrice
FROM cte;
If it is possible that a single person has two entries for exactly the same SaleTS then RANK() OVER(...)
should be used instead.