SQL

Common Table Expressions, or CTEs as they are often called, are an area of SQL which can by some be considered to be no different than magic. This is because few of us use them, and even fewer of us use them regularly enough to make them like the familiar of some powerful wizard in some book. And just like those familiars sometimes do in the books, they can give us great frustration or even turn upon us like some demon or Djinn who has escaped the bounds we thought would control them.