Use Cases for Subqueries

The use of subqueries is not limited to insertion. Subqueries can be used in a variety of scenarios.

The Tournament database

To demonstrate different use cases of subqueries, we’ll use the Tournament database, which consists of these tables:

• ActionPoints stores points earned by a player for some in-game action:

  • Id: Uniquely identifies each action performed within a game.
  • PlayerId: References the Id column of the Players table.
  • Points: represented the number of points earned.

• Players stores information about players participating in the game:

  • Id: Uniquely identifies each player.
  • Name: The player name.
  • TeamId: References the Id column of the Teams table and represents the team to which the player belongs.

• Teams stores information about teams:

  • Id: Uniquely identifies each team.
  • Name: The team name.