I have a summary dataset that I group by a particular variable. There are days when a category may produce no records.  Since SAS does not produce a zero value output when no input data is generated, I created a second table with zero values for each category which I want to combine with the summary dataset to produce a complete output set that populates each category group (zeros for categories with no data). Let me show the two datasets:   Set1                                                                   Date    Category   Accts   Dollars 1/5/21   1-10          12       $1000 1/5/21   21-30        30       $9800 1/5/21   31-40        83       $15430 1/5/21   41-50        110      $23090 1/5/21    51-60        27       $8500   Set2 Category   Accts   Dollars 0               0           0 1-10          0           0 11-20        0           0 21-30        0           0 31-40        0           0 41-50        0           0 51-60        0           0 61-70        0           0 71-80        0           0 81-90        0           0 91-100       0           0   I want to use the UNION operator to join the two data sets that will keep the populated rows intact from Set 1 while bringing in the  rows with the zero value categories from Set 2 that weren't populated in Set 1.  The output data set should look like Set 3 below:   Set 3 Date    Category   Accts   Dollars 1/5/21      0              0          0 1/5/21   1-10          12       $1000 1/5/21   11-20        0           0 1/5/21   21-30        30       $9800 1/5/21   31-40        83       $15430 1/5/21   41-50        110      $23090 1/5/21    51-60        27       $8500 1/5/21    61-70        0           0 1/5/21    71-80        0           0 1/5/21    81-90        0           0 1/5/21   91-100       0           0   I have enclosed the code I am using to perform this task but it's not producing the above output.   proc sql; create table set3 as select a.date, a.category, a.accts, a.dollars from set1 a group by a.category having accts gt 0 and dollars gt 0 union select b.category, b.accts, b.dollars,0 from set2 b; quit;   From my query, the following errors are generated in the log file:   ERROR: Column 1 from the first contributor of UNION is not the same type as its counterpart from the second. ERROR: Column 2 from the first contributor of UNION is not the same type as its counterpart from the second   Any assistance would be greatly appreciated.  Thanks. ... View more