I’m trying to test a small script in snowflake that performs housekeeping on a couple of tables, but the script is terminating with Syntax error: unexpected 'DELETE' error.

My script is:

DECLARE
    AnalysisDate DATE;
    HouseKeepingDate DATE;
    RetentionDays INT;
    
AnalysisDate := '2024-06-27';
RetentionDays := 28;
HouseKeepingDate := DATEADD(DAY, -:RetentionDays, :AnalysisDate);

DELETE t 
FROM PREP.STOCK_ADJUSTMENTS AS t
WHERE ANALYSIS_DATE < :HouseKeepingDate;

DELETE t 
FROM PREP.BOOK_STOCK AS t
WHERE ANALYSIS_DATE < :HouseKeepingDate;

I get the same error with or without putting in the table alias.