How To Look For A Customer And A Date At The Same Time

i have 2 dilemmas

**dilemma 1**

i have a date of purchase in column A

i have a customer number in column B

now if i want to search for a date and for it to display the results from columns C,D,E and F (purchased items) i know i use HLOOKUP

but how would i look for a customer and a date at the same time.

**dilemma 2**

i want to be able to put in a customer number and excel to tell me all the dates they purchased items.

currently i use

={IFERROR(INDEX(Table1[DATE],SMALL(IF(Table1[NUM]=$L$3,ROW(Table1[NUM])-MIN(ROW(Table1[NUM]))+1),ROWS($1:1))),"error")}

and i change the ROWS($1:1) to ROWS($1:2) or ROWS($1:3) etc

to bring in that result, but i want it to bring in unique dates, as a customer might ring us back with another purchase on the same date and i dont want it to duplicate the date.