check(_:)

For example:

// CREATE TABLE player (
//   personalPhone TEXT,
//   workPhone TEXT,
//   CHECK personalPhone IS NOT NULL OR workPhone IS NOT NULL
// )
try db.create(table: "player") { t in
    t.column("personalPhone", .text)
    t.column("workPhone", .text)
    let personalPhone = Column("personalPhone")
    let workPhone = Column("workPhone")
    t.check(personalPhone != nil || workPhone != nil)
}

When defining a check constraint on a single column, you can use the check(_:) shortcut:

// CREATE TABLE player(
//   name TEXT CHECK (LENGTH(name) > 0)
// )
try db.create(table: "player") { t in
    t.column("name", .text).check { length($0) > 0 }
}

Related SQLite documentation: https://www.sqlite.org/lang_createtable.html#ckconst