PQL

The Limit() query returns some subset of record IDs / keys from a given row call based on the limit and offset arguments provided.

Limit() is a row call.

Call Definition

Limit(ROW_CALL, limit=UINT, offset=UINT)

Mandatory Arguments

• ROW_CALL : the row call to be limited

Optional Arguments

• limit : the number of records you’d like to limit the query to. For example, limit=0 returns nothing and limit=100 returns 100 records. This is an optional argument. If it’s not supplied there will be no limit on the number of records returned.
• offset : the offset from the beginning you’d like to use. For example, offset=0 starts at the beginning and could potentially return all the records. An offset=100 will start returning records after the first 100 that would have been returned by the ROW_CALL. This is an optional argument. If it’s not supplied there will be no offset applied.

Returns

• list of record IDs or record keys

Examples

Data:

Index: customer

 _id | age |     has_bought	 |    last_purchase
-----+-----+---------------------+----------------------
 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

Example 1

Return the first 3 record IDs

Query

[customer]Limit(All(), limit=3)

Tabular Response

 _id
-----
 0
 1
 2

HTTP Response

{
  "results": [
    {
      "columns": [
        0,
        1,
        2
      ]
    }
  ]
}

Explanation

The first 3 record IDs are 0, 1, 2. No offset was applied so we start at the beginning.

Example 2

Return 3 record IDs but start after the first record

Query

[customer]Limit(All(), limit=3, offset=1)

Tabular Response

 _id
-----
 1
 2
 3

HTTP Response

{
  "results": [
    {
      "columns": [
        1,
        2,
        3
      ]
    }
  ]
}

Explanation

Offset of one means we start at the second record. Then we get a limit of 3 records which are 1, 2, 3.

Example 3

Return the third record ID

Query

[customer]Limit(All(), limit=1, offset=2)

Tabular Response

 _id
-----
 2

HTTP Response

"results": [
    {
       "columns": [
         2
       ]
    }
]

Explanation

Offset of 2 means we start at the third record. Limit of 1 means we will only get one record - i.e. the third record.

Example 4

Return Limit() using the default values.

Query

[customer]Limit(All())

Tabular Response

 _id
-----
 0
 1
 2
 3
 4
 5

HTTP Response

{
  "results": [
    {
      "columns": [
        0,
        1,
        2,
        3,
        4,
        5
      ]
    }
  ]
}

Explanation

As we can see, if limit and offset arguments aren’t supplied we get the same results as an All() query.