allow SAS to derive the start date for "last-quarter"
Something like [pre] %let qtr_start = %sysfunc( intnx( qtr, "&sysdate"d, 0 ), date9 );
where transaction_date GE "&qtr_start"d [/pre]
but that depends on using a suitable format for the quarter date.
With "implicit-pass-thru" the SAS engine will do any reformatting from DATE9 to the style for your dbms. If you are using 'explicit-pass-thru' you need to prepare the proper format