IsDatabase

IsDatabase( value )
IsDatabase( value )
IsDatabase( value )
IsDatabase( value )
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Description

The IsDatabase function returns true only if value is a database document, otherwise it returns false.

Parameters

Argument Type Definition and Requirements

value

Any

Any value, which is to be tested to determine whether it is a database document or not.

Returns

Returns a boolean, indicating whether value was a database document or not.

Examples

The following query uses Map to iterate over an array of all of the types of values that can be tested by a type-check function, passing each item into a Lambda function that returns an object, which contains the value and the result of calling IsDatabase with that value:

result, err := client.Query(
  f.Map(
    f.Arr{
      f.Arr{"array"},
      true,
      false,
      f.BytesV{0x01, 0x02, 0x03, 0x04},
      f.Arr{0x1, 0x2, 0x3, 0x4},
      f.Collection("Letters"),
      f.Ref("credentials/self"),
      f.Database("child_db"),
      f.Date("2019-11-12"),
      f.RefCollection(f.Collection("Letters"), 123),
      10.1,
      f.Function("double"),
      f.Index("all_letters"),
      10,
      f.RefCollection(f.Keys(), "248967241620521472"),
      f.Query(f.Lambda("x", f.Var("x"))),
      nil,
      f.Null(),
      f.Obj{ "x": 10 },
      f.Role("employees"),
      f.Match(f.Index("all_letters")),
      "ten",
      "10",
      f.Now(),
      f.RefCollection(f.Tokens(), "249062079147803136"),
    },
    f.Lambda("x", f.Obj{
      "value": f.Var("x"),
      "IsDatabase": f.IsDatabase(f.Var("x")),
    })))

if (err != nil) {
  fmt.Println(err)
} else {
  fmt.Println(result)
}
System.out.println(
    client.query(
        Map(
            Arr(
                Arr(Value("array")),
                Value(true),
                Value(false),
                Value(new byte[] {0x1, 0x2, 0x3, 0x4}),
                Arr(Value(0x1), Value(0x2), Value(0x3), Value(0x4)),
                Collection("Letters"),
                Ref("credentials/self"),
                Database("child_db"),
                Date("2019-11-12"),
                Ref(Collection("Letters"), "123"),
                Value(10.1),
                Function("double"),
                Index("all_letters"),
                Value(10),
                Ref(Keys(), "248967241620521472"),
                Query(Lambda("x", Var("x"))),
                Null(),
                Obj("x", Value(10)),
                Role("employees"),
                Match(Index("all_letters")),
                Value("ten"),
                Value("10"),
                Now(),
                Ref(Tokens(), "249062079147803136")
            ),
            Lambda(
                "x",
                Obj("value", Var("x"), "IsDatabase", IsDatabase(Var("x")))
            )
        )
    ).get());
client.query(
  q.Map(
    [
      ['array'],
      true,
      false,
      new Uint8Array([1, 2, 3, 4]),
      [0x1, 0x2, 0x3, 0x4],
      q.Collection('Letters'),
      q.Ref('credentials/self'),
      q.Database('child_db'),
      q.Date('2019-11-12'),
      q.Ref(q.Collection('Letters'), 123),
      10.1,
      q.Function('double'),
      q.Index('all_letters'),
      10,
      q.Ref(q.Keys(), '248967241620521472'),
      q.Query(q.Lambda('x', q.Var('x'))),
      null,
      { x: 10 },
      q.Role('employees'),
      q.Match(q.Index('all_letters')),
      'ten',
      '10',
      q.Now(),
      q.Ref(q.Tokens(), '249062079147803136'),
    ],
    q.Lambda('x', {
      value: q.Var('x'),
      IsDatabase: q.IsDatabase(q.Var('x')),
    })
  )
)
.then((ret) => console.log(ret))
println(Await.result(
  client.query(
    Map(
      Arr(
        Arr("array"),
        true,
        false,
        BytesV(0x1, 0x2, 0x3, 0x4),
        Arr(0x1, 0x2, 0x3, 0x4),
        Collection("Letters"),
        Ref("credentials/self"),
        Database("child_db"),
        Date("2019-11-12"),
        Ref(Collection("Letters"), 123),
        10.1,
        Function("double"),
        Index("all_letters"),
        10,
        Ref(Keys(), "248967241620521472"),
        Query(Lambda("x", Var("x"))),
        Null,
        Obj("x" -> 10),
        Role("employees"),
        Match(Index("all_letters")),
        "ten",
        "10",
        Now(),
        Ref(Tokens(), "249062079147803136")
      ),
      Lambda(
        "x",
        Obj( "value" -> Var("x"), "IsDatabase" -> IsDatabase(Var("x")))
      )
    )
  ),
  5.seconds
))
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Not available in this language yet.
Not available in this language yet.
Not available in this language yet.
[map[IsDatabase:false value:[array]] map[IsDatabase:false value:true] map[IsDatabase:false value:false] map[IsDatabase:false value:[1 2 3 4]] map[IsDatabase:false value:[1 2 3 4]] map[IsDatabase:false value:{Letters 0xc0002101b0 0xc0002101b0 <nil>}] map[IsDatabase:false value:{264354436692836874 0xc0002102d0 0xc0002102d0 <nil>}] map[IsDatabase:true value:{child_db 0xc0002103f0 0xc0002103f0 <nil>}] map[IsDatabase:false value:{0 63709113600 <nil>}] map[IsDatabase:false value:{123 0xc000210600 0xc000210600 <nil>}] map[IsDatabase:false value:10.1] map[IsDatabase:false value:{double 0xc000210750 0xc000210750 <nil>}] map[IsDatabase:false value:{all_letters 0xc000210870 0xc000210870 <nil>}] map[IsDatabase:false value:10] map[IsDatabase:false value:{248967241620521472 0xc0002109c0 0xc0002109c0 <nil>}] map[IsDatabase:false value:{[123 34 108 97 109 98 100 97 34 58 34 120 34 44 34 101 120 112 114 34 58 123 34 118 97 114 34 58 34 120 34 125 125]}] map[IsDatabase:false value:{}] map[IsDatabase:false value:{}] map[IsDatabase:false value:map[x:10]] map[IsDatabase:false value:{employees 0xc000210bd0 0xc000210bd0 <nil>}] map[IsDatabase:false value:{map[match:{all_letters 0xc000210d20 0xc000210d20 <nil>}]}] map[IsDatabase:false value:ten] map[IsDatabase:false value:10] map[IsDatabase:false value:{805429000 63724302225 <nil>}] map[IsDatabase:false value:{249062079147803136 0xc000210ed0 0xc000210ed0 <nil>}]]
[{value: ["array"], IsDatabase: false},
 {value: true, IsDatabase: false},
 {value: false, IsDatabase: false},
 {value: [0x01 0x02 0x03 0x04], IsDatabase: false},
 {value: [1, 2, 3, 4], IsDatabase: false},
 {value: ref(id = "Letters", collection = ref(id = "collections")),
  IsDatabase: false},
 {value: ref(id = "248967019900174848", collection = ref(id = "credentials")),
  IsDatabase: false},
 {value: ref(id = "child_db", collection = ref(id = "databases")),
  IsDatabase: true},
 {value: 2019-11-12, IsDatabase: false},
 {value: ref(id = "123", collection = ref(id = "Letters", collection = ref(id = "collections"))),
  IsDatabase: false},
 {value: 10.1, IsDatabase: false},
 {value: ref(id = "double", collection = ref(id = "functions")),
  IsDatabase: false},
 {value: ref(id = "all_letters", collection = ref(id = "indexes")),
  IsDatabase: false},
 {value: 10, IsDatabase: false},
 {value: ref(id = "248967241620521472", collection = ref(id = "keys")),
  IsDatabase: false},
 {value: QueryV({lambda=x, expr={var=x}}), IsDatabase: false},
 {value: null, IsDatabase: false},
 {value: {x: 10}, IsDatabase: false},
 {value: ref(id = "employees", collection = ref(id = "roles")),
  IsDatabase: false},
 {value: {@set = {match: ref(id = "all_letters", collection = ref(id = "indexes"))}},
  IsDatabase: false},
 {value: "ten", IsDatabase: false},
 {value: "10", IsDatabase: false},
 {value: 2019-11-12T13:15:16.789Z, IsDatabase: false},
 {value: ref(id = "249062079147803136", collection = ref(id = "tokens")),
  IsDatabase: false}]
[ { value: [ 'array' ], IsDatabase: false },
  { value: true, IsDatabase: false },
  { value: false, IsDatabase: false },
  { value: Bytes("AQIDBA=="), IsDatabase: false },
  { value: [ 1, 2, 3, 4 ], IsDatabase: false },
  { value: Collection("Letters"), IsDatabase: false },
  { value: Ref(Credentials(), "248967019900174848"),
    IsDatabase: false },
  { value: Database("child_db"), IsDatabase: true },
  { value: Date("2019-11-12"), IsDatabase: false },
  { value: Ref(Collection("Letters"), "123"), IsDatabase: false },
  { value: 10.1, IsDatabase: false },
  { value: Function("double"), IsDatabase: false },
  { value: Index("all_letters"), IsDatabase: false },
  { value: 10, IsDatabase: false },
  { value: Ref(Keys(), "248967241620521472"), IsDatabase: false },
  { value: Query(Lambda("x", Var("x"))), IsDatabase: false },
  { value: null, IsDatabase: false },
  { value: { x: 10 }, IsDatabase: false },
  { value: Role("employees"), IsDatabase: false },
  { value: Match(Index("all_letters")), IsDatabase: false },
  { value: 'ten', IsDatabase: false },
  { value: '10', IsDatabase: false },
  { value: Time("2019-11-12T13:15:16.789Z"), IsDatabase: false },
  { value: Ref(Tokens(), "249062079147803136"),
    IsDatabase: false } ]
[{value: ["array"], IsDatabase: false},
 {value: true, IsDatabase: false},
 {value: false, IsDatabase: false},
 {value: [0x01 0x02 0x03 0x04], IsDatabase: false},
 {value: [1, 2, 3, 4], IsDatabase: false},
 {value: ref(id = "Letters", collection = ref(id = "collections")),
  IsDatabase: false},
 {value: ref(id = "248967019900174848", collection = ref(id = "credentials")),
  IsDatabase: false},
 {value: ref(id = "child_db", collection = ref(id = "databases")),
  IsDatabase: true},
 {value: 2019-11-12, IsDatabase: false},
 {value: ref(id = "123", collection = ref(id = "Letters", collection = ref(id = "collections"))),
  IsDatabase: false},
 {value: 10.1, IsDatabase: false},
 {value: ref(id = "double", collection = ref(id = "functions")),
  IsDatabase: false},
 {value: ref(id = "all_letters", collection = ref(id = "indexes")),
  IsDatabase: false},
 {value: 10, IsDatabase: false},
 {value: ref(id = "248967241620521472", collection = ref(id = "keys")),
  IsDatabase: false},
 {value: {lambda: "x", expr: {var: "x"}}, IsDatabase: false},
 {value: NullV, IsDatabase: false},
 {value: {x: 10}, IsDatabase: false},
 {value: ref(id = "employees", collection = ref(id = "roles")), IsDatabase: false},
 {value: {@set = {match: ref(id = "all_letters", collection = ref(id = "indexes"))}},
  IsDatabase: true},
 {value: "ten", IsDatabase: false},
 {value: "10", IsDatabase: false},
 {value: 2019-11-12T13:15:16.789Z, IsDatabase: false},
 {value: ref(id = "249062079147803136", collection = ref(id = "tokens")),
  IsDatabase: false}]

This query operates on a pre-existing schema, which is not provided here.

Also, the query is executed via a client connection, that uses a secret acquired by calling Login (not shown here), so that Ref("credentials/self") returns a valid value.

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