Having Group By Clauses — elein’s GeneralBits

Some people go to great lengths to avoid GROUP BY and HAVING clauses in their queries. The error messages are fussy but they are usually right. GROUP BY and HAVING key words are essential for good SQL reporting. The primary reason for GROUP BY is to reduce the number of rows, usually by aggregation. It […]


 LATERAL The primary feature of LATERAL JOIN is to enable access elements of a main query in a subquery which can be very powerful. Several common uses of LATERAL are to: denormalize arrays into parent child tables aggregation across several tables row or action generation. Note, however, that the subquery will execute for each main […]