SQL JOINS allows you to combine records for multiple tables based on some condition. This condition, in most cases, is “common…
SQL TABLE EXPRESSION gives you the power to create a temporary table inside a query. The life of this temporary table is only inside that query. As soon as the query is completed temporary table will vanish.
With the “GROUP BY” clause, SQL accepts a single set of columns, and based on that set final result…
ROLLUP and CUBE both are extensions for the “GROUP BY” clause.
To understand RANK and DENSE_RANK functions, let's examine how participants are ranked in…