AssociationToMany

The number of associated records.

It has a default name, which is [key]Count, where key is the key of the association. For example:

For example:

struct TeamInfo: FetchableRecord, Decodable {
    var team: Team
    var playerCount: Int
}
let request = Team.annotated(with: Team.players.count())
let infos: [TeamInfo] = try TeamInfo.fetchAll(db, request)

let teams: [Team] = try Team.having(Team.players.count() > 10).fetchAll(db)

Creates an aggregate that is true if there exists no associated records.

It has a default name, which is hasNo[Key], where key is the key of the association. For example:

struct TeamInfo: FetchableRecord, Decodable {
    var team: Team
    var hasNoPlayer: Bool
}
let request = Team.annotated(with: Team.players.isEmpty())
let infos: [TeamInfo] = try TeamInfo.fetchAll(db, request)

let teams: [Team] = try Team.having(Team.players.isEmpty()).fetchAll(db)
let teams: [Team] = try Team.having(!Team.players.isEmpty())
let teams: [Team] = try Team.having(Team.players.isEmpty() == false)

Creates an aggregate which evaluate to the average value of the given expression in associated records.

When the averaged expression is a column, the aggregate has a default name which is average[Key][Column], where key is the key of the association. For example:

For example:

struct TeamInfo: FetchableRecord, Decodable {
    var team: Team
    var averagePlayerScore: Double
}
let request = Team.annotated(with: Team.players.average(Column("score")))
let infos: [TeamInfo] = try TeamInfo.fetchAll(db, request)

let teams: [Team] = try Team.having(Team.players.average(Column("score")) > 100).fetchAll(db)

Creates an aggregate which evaluate to the maximum value of the given expression in associated records.

When the maximized expression is a column, the aggregate has a default name which is maximum[Key][Column], where key is the key of the association. For example:

For example:

struct TeamInfo: FetchableRecord, Decodable {
    var team: Team
    var maxPlayerScore: Double
}
let request = Team.annotated(with: Team.players.max(Column("score")))
let infos: [TeamInfo] = try TeamInfo.fetchAll(db, request)

let teams: [Team] = try Team.having(Team.players.max(Column("score")) < 100).fetchAll(db)

Creates an aggregate which evaluate to the minimum value of the given expression in associated records.

When the minimized expression is a column, the aggregate has a default name which is minimum[Key][Column], where key is the key of the association. For example:

For example:

struct TeamInfo: FetchableRecord, Decodable {
    var team: Team
    var minPlayerScore: Double
}
let request = Team.annotated(with: Team.players.min(Column("score")))
let infos: [TeamInfo] = try TeamInfo.fetchAll(db, request)

let teams: [Team] = try Team.having(Team.players.min(Column("score")) > 100).fetchAll(db)

Creates an aggregate which evaluate to the sum of the given expression in associated records.

When the summed expression is a column, the aggregate has a default name which is [key][Column]Sum, where key is the key of the association. For example:

For example:

struct TeamInfo: FetchableRecord, Decodable {
    var team: Team
    var playerScoreSum: Double
}
let request = Team.annotated(with: Team.players.sum(Column("score")))
let infos: [TeamInfo] = try TeamInfo.fetchAll(db, request)

let teams: [Team] = try Team.having(Team.players.sum(Column("score")) > 100).fetchAll(db)