Miscellaneous Utility Functions

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    Meta functions retrieve information about the document or item as well as perform base64 encoding.

    BASE64(expression)

    Returns the base64 encoding of the given expression.

    BASE64_ENCODE(expression)

    Alias of BASE64().

    BASE64_DECODE(expression)

    Reverses the encoding done by the BASE64() or BASE64_ENCODE() functions.

    META( [ keyspace_expr ] ) [ .property ]

    This function returns the metadata for the document or keyspace specified by keyspace_expr. The metadata is returned as a JSON object.

    To return a single property from the metadata, you must use a nested expression containing the META() function and the required property, for example META().id. The supported metadata properties are described below.

    You can use the META() function with a property to index metadata information. Only certain metadata properties are indexable; these are indicated in the description below.

    You can also use the META() function with a property in the predicate of an ANSI JOIN Clause.

    Arguments

    keyspace_expr

    [Optional. Default is current keyspace.]

    String or an expression that results in a keyspace or a document. This argument is not required when creating an index, since the META() function implicitly uses the keyspace being indexed.

    property

    [Optional] The name of a single metadata property. The property name must be separated from the META() function by a dot (.) and may be one of the following:

    cas

    Value representing the current state of an item which changes every time the item is modified. For details, refer to Concurrent Document Mutations.

    This property is indexable.

    expiration

    Value representing a document’s expiration date. A value of 0 (zero) means no expiration date. For details, refer to KV Operations.

    This property is indexable.

    flags

    Value set by the SDKs for non-JSON documents. For details, refer to Non-JSON Documents.

    This property is not indexable. If you attempt to build an index on this property, an error is returned.

    id

    Value representing a document’s unique ID number.

    This property is indexable.

    type

    Value for the type of document; currently only json is supported.

    This property is not indexable. If you attempt to build an index on this property, an error is returned.

    Return Value

    The bare function returns a JSON object containing the specified document’s metadata. When the function is used with a property as part of a nested expression, the expression returns the JSON value of the property.

    Examples

    Example 1. Return all metadata
    SELECT META() AS metadata
    FROM `travel-sample`
    LIMIT 3;
    Results
    [
      {
          "metadata": {
              "cas": 1583859008179798016,
              "expiration": 0,
              "flags": 33554432,
              "id": "airline_10",
              "type": "json"
          }
      },
      {
          "metadata": {
              "cas": 1583859008180846592,
              "expiration": 0,
              "flags": 33554432,
              "id": "airline_10123",
              "type": "json"
          }
      },
      {
          "metadata": {
              "cas": 1583859008181895168,
              "expiration": 0,
              "flags": 33554432,
              "id": "airline_10226",
              "type": "json"
          }
      }
    ]
    Example 2. Return a single metadata property
    SELECT META().id AS id
    FROM `travel-sample`
    LIMIT 3;
    Results
    [
      {
        "id": "airline_10"
      },
      {
        "id": "airline_10123"
      },
      {
        "id": "airline_10226"
      }
    ]
    Example 3. Return a single metadata property for a specified keyspace
    SELECT META(route).id AS id (1)
    FROM `travel-sample` AS route
    JOIN `travel-sample` AS airport
    ON route.sourceairport = airport.faa
    WHERE airport.city = "Paris"
    LIMIT 3;
    Results
    [
      {
        "id": "route_10136"
      },
      {
        "id": "route_10137"
      },
      {
        "id": "route_10138"
      }
    ]
    1 You must specify a keyspace for the META() function because there is more than one FROM term.

    For examples showing how to index metadata information, refer to Indexing Meta Info.

    For examples showing how to use metadata information in the predicate of an ANSI JOIN clause, refer to JOIN Clause.

    PAIRS(obj)

    This function generates an array of arrays of [field_name, value] pairs of all possible fields in the given JSON object obj.

    Nested sub-object fields are explored recursively.

    Arguments

    obj

    a valid JSON object

    Return Value

    Array of [field_name, value] arrays for each field in the input object obj.

    • If obj has nested objects, then fields of such nested sub-objects are also explored and corresponding inner-array elements are produced.

    • If obj is an array, then each element of the array is explored and corresponding inner-array elements are produced.

    • If obj is a primitive data type of integer or string, then it returns NULL, as they don’t have a name.

    • If obj is an array of primitive data types, then it returns an empty array [].

    • If obj is an array of objects, then it returns an array of objects.

    When the field_name is in curly brackets, it’s treated as an array and returns an array; but without curly bracket, it’s treated as a primitive data type and returns NULL. For example,

    • PAIRS(public_likes) returns NULL

    • PAIRS({public_likes}) returns an array

    Examples

    Example 4. Input value of a nested object
    SELECT t        AS orig_t,
           PAIRS(t) AS pairs_t
    FROM   `travel-sample` t
    WHERE  type = "airport"
    LIMIT  1;
    Result
    [
      {
        "orig_t": {
          "airportname": "Calais Dunkerque",
          "city": "Calais",
          "country": "France",
          "faa": "CQF",
          "geo": {
            "alt": 12,
            "lat": 50.962097,
            "lon": 1.954764
          },
          "icao": "LFAC",
          "id": 1254,
          "type": "airport",
          "tz": "Europe/Paris"
        },
        "pairs_t": [
          [
            "id",
            1254
          ],
          [
            "city",
            "Calais"
          ],
          [
            "faa",
            "CQF"
          ],
          [
            "geo",
            {
              "alt": 12,
              "lat": 50.962097,
              "lon": 1.954764
            }
          ],
          [
            "lon",
            1.954764
          ],
          [
            "alt",
            12
          ],
          [
            "lat",
            50.962097
          ],
          [
            "type",
            "airport"
          ],
          [
            "tz",
            "Europe/Paris"
          ],
          [
            "airportname",
            "Calais Dunkerque"
          ],
          [
            "country",
            "France"
          ],
          [
            "icao",
            "LFAC"
          ]
        ]
      }
    ]
    Example 5. Input value of an array
    SELECT public_likes          AS orig_t,
           PAIRS(public_likes)   AS pairs_array_t,
           PAIRS({public_likes}) AS pairs_obj_t
    FROM   `travel-sample`
    WHERE  type = "hotel"
    LIMIT  1;
    Result
    [
      {
        "orig_t": [
          "Julius Tromp I",
          "Corrine Hilll",
          "Jaeden McKenzie",
          "Vallie Ryan",
          "Brian Kilback",
          "Lilian McLaughlin",
          "Ms. Moses Feeney",
          "Elnora Trantow"
        ],
        "pairs_array_t": [],
        "pairs_obj_t": [
          [
            "public_likes",
            [
              "Julius Tromp I",
              "Corrine Hilll",
              "Jaeden McKenzie",
              "Vallie Ryan",
              "Brian Kilback",
              "Lilian McLaughlin",
              "Ms. Moses Feeney",
              "Elnora Trantow"
            ]
          ],
          [
            "public_likes",
            "Julius Tromp I"
          ],
          [
            "public_likes",
            "Corrine Hilll"
          ],
          [
            "public_likes",
            "Jaeden McKenzie"
          ],
          [
            "public_likes",
            "Vallie Ryan"
          ],
          [
            "public_likes",
            "Brian Kilback"
          ],
          [
            "public_likes",
            "Lilian McLaughlin"
          ],
          [
            "public_likes",
            "Ms. Moses Feeney"
          ],
          [
            "public_likes",
            "Elnora Trantow"
          ]
        ]
      }
    ]
    Example 6. Input value of a primitive (field document string) data type
    SELECT country        AS orig_t,
           PAIRS(country) AS pairs_t
    FROM   `travel-sample`
    WHERE  type = "airport"
    LIMIT  1;
    Result
    [
      {
        "orig_t": "France",
        "pairs_t": null
      }
    ]
    Example 7. Input value of a primitive (constant) data type
    SELECT PAIRS("N1QL")             AS constant_string,
           PAIRS(4)                  AS constant_int,
           PAIRS([1,2,3])            AS constant_int_array,
           PAIRS({"name" : 3})       AS object_constant_int,
           PAIRS({"name" : [1,2,3]}) AS object_constant_int_array;
    Result
    [
      {
        "constant_int": null,
        "constant_int_array": [],
        "constant_string": null,
        "object_constant_int": [
          [
            "name",
            3
          ]
        ],
        "object_constant_int_array": [
          [
            "name",
            [
              1,
              2,
              3
            ]
          ],
          [
            "name",
            1
          ],
          [
            "name",
            2
          ],
          [
            "name",
            3
          ]
        ]
      }
    ]
    Example 8. Input value of an array of objects
    SELECT reviews[*].ratings,
           PAIRS({reviews[*].ratings}) AS pairs_t
    FROM   `travel-sample`
    WHERE  type = "hotel"
    LIMIT  1;
    Result
    [
      {
        "pairs_t": [
          [
            "ratings",
            [
              {
                "Cleanliness": 5,
                "Location": 4,
                "Overall": 4,
                "Rooms": 3,
                "Service": 5,
                "Value": 4
              },
              {
                "Business service (e.g., internet access)": 4,
                "Check in / front desk": 4,
                "Cleanliness": 4,
                "Location": 4,
                "Overall": 4,
                "Rooms": 3,
                "Service": 3,
                "Value": 5
              }
            ]
          ],
          [
            "ratings",
            {
              "Cleanliness": 5,
              "Location": 4,
              "Overall": 4,
              "Rooms": 3,
              "Service": 5,
              "Value": 4
            }
          ],
          [
            "ratings",
            {
              "Business service (e.g., internet access)": 4,
              "Check in / front desk": 4,
              "Cleanliness": 4,
              "Location": 4,
              "Overall": 4,
              "Rooms": 3,
              "Service": 3,
              "Value": 5
            }
          ],
          [
            "Cleanliness",
            5
          ],
          [
            "Location",
            4
          ],
          [
            "Overall",
            4
          ],
          [
            "Rooms",
            3
          ],
          [
            "Service",
            5
          ],
          [
            "Value",
            4
          ],
          [
            "Cleanliness",
            4
          ],
          [
            "Location",
            4
          ],
          [
            "Rooms",
            3
          ],
          [
            "Value",
            5
          ],
          [
            "Business service (e.g., internet access)",
            4
          ],
          [
            "Check in / front desk",
            4
          ],
          [
            "Overall",
            4
          ],
          [
            "Service",
            3
          ]
        ],
        "ratings": [
          {
            "Cleanliness": 5,
            "Location": 4,
            "Overall": 4,
            "Rooms": 3,
            "Service": 5,
            "Value": 4
          },
          {
            "Business service (e.g., internet access)": 4,
            "Check in / front desk": 4,
            "Cleanliness": 4,
            "Location": 4,
            "Overall": 4,
            "Rooms": 3,
            "Service": 3,
            "Value": 5
          }
        ]
      }
    ]

    UUID()

    Returns a version 4 universally unique identifier (UUID).