Documentation

ConstRow()

The ConstRow() query returns a set of record IDs / keys defined explicitly by the columns argument (list of record IDs / keys). This can be useful if you have a predetermined set of records you want to use as the argument of another call – see the last example below. ConstRow() is a row call.

Call Definition:

 ConstRow(columns = [LIST_OF_RECORD_IDS])

Mandatory Arguments

  • columns : the list of record IDs or record keys to return. LIST_OF_RECORD_IDS must be record IDs or record keys in comma seperated list – e.g. 0, 5, 20.

Optional Arguments

Returns

  • list of record IDs / keys

Examples

Data:

Index: customer (non keyed index)

 _id | age (Int) | has_purchased (Set) | last_purchase (Timestamp)
-----+-----------+---------------------+---------------------------
 0   |    23     | ["brand1","brand2"] | 2021-01-05T08:30:00Z
 1   |    31     | ["brand1","brand3"] | 2020-09-12T12:30:00Z
 2   |    28     | ["brand1","brand3"] | 2021-08-06T16:15:00Z
 3   |    19     | []                  | null
 4   |    25     | ["brand1","brand4"] | 2021-10-01T20:45:00Z
 5   |    40     | ["brand4"]          | 2022-01-13T11:00:00Z

Index: customer_keyed (keyed index)

 _id | age (Int) | has_purchased (Set) | last_purchase (Timestamp)
-----+-----------+---------------------+---------------------------
 a   |    23     | ["brand1","brand2"] | 2021-01-05T08:30:00Z
 b   |    31     | ["brand1","brand3"] | 2020-09-12T12:30:00Z
 c   |    28     | ["brand1","brand3"] | 2021-08-06T16:15:00Z
 d   |    19     | []                  | null
 e   |    25     | ["brand1","brand4"] | 2021-10-01T20:45:00Z
 f   |    40     | ["brand4"]          | 2022-01-13T11:00:00Z

Example 1:

Return record IDs 0 and 1 – non-keyed index.

Query

[customer]ConstRow(columns = [0,1])

Tabular Response

 _id
-----
 0
 1

HTTP Response

{
  "results": [
    {
      "columns": [
        0,
        1
      ]
    }
  ]
}

Explanation:

Result with the record IDs asked for – 0 and 1.


Example 2:

Return record keys a and b – non keyed index.

Query

[customer_keyed]ConstRow(columns = [a,b])

Tabular Response

 _id
-----
 a
 b

HTTP Response

{
  "results": [
    {
      "columns": [],
      "keys": [
        "a",
        "b"
      ]
    }
  ]
}

Explanation:

Result with the record keys asked for - a and b.


Example 3

Select / extract the age and has_purchased events for the record with ID 0 or 1

[customer]Extract(
  ConstRow(columns = [0,1]),
  Rows(age),
  Rows(has_purchased)
)

Tabular Response

 _id | age |    has_purchased
-----+-----+---------------------
 0   | 23  | ["brand1","brand2"]
 1   | 31  | ["brand1","brand3"]

HTTP Response

{
  "results": [
    {
      "fields": [
        {
          "name": "age",
          "type": "int64"
        },
        {
          "name": "has_purchased",
          "type": "[]string"
        }
      ],
      "columns": [
        {
          "column": 0,
          "rows": [
            23,
            [
              "brand1",
              "brand2"
            ]
          ]
        },
        {
          "column": 1,
          "rows": [
            31,
            [
              "brand1",
              "brand3"
            ]
          ]
        }
      ]
    }
  ]
}

Explanation:

The first argument of Extract() is a row call - this tells Extract() what records you want values for. Here we use ConstRow() (as opposed to another row call) to tell Extract() the specific records to use. Rows(age) and Rows(has_purchased) tell Extract() we like to return the data in the age and has_purchased field. View Extract() for more on Extract().

Something missing or incorrect?
Help improve this article or join us on Discord!

© 2022 Molecula Corp. (DBA FeatureBase). All rights reserved.