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Getting Started with Reading Data from Table

The easiest way to retrieve data from a table is to send a GET request with the table name.

Table Access Rules
  • If the database user/role has permission to access the table then it will be considered for query.
  • In case the user has access to multiple schama, the table name must be unique if DB2Rest is not running in multi-tenant mode.
curl --request GET \
--url http://localhost:8080/film \
--header 'Accept-Profile: ' \
--header 'User-Agent: insomnia/8.4.5'

DB2Rest will respond with HTTP status code 200 and return a list of results.

HTTP/1.1 200
Content-Type: application/json
Transfer-Encoding: chunked

[
	{
		"film_id": 1,
		"title": "ACADEMY DINOSAUR",
		"description": "A Epic Drama of a Feminist And a Mad Scientist who must Battle a Teacher in The Canadian Rockies",
		"release_year": "2006-01-01",
		"language_id": 1,
		"original_language_id": null,
		"rental_duration": 6,
		"rental_rate": 0.99,
		"length": 86,
		"replacement_cost": 20.99,
		"rating": "PG",
		"special_features": "Deleted Scenes,Behind the Scenes",
		"last_update": "2006-02-15T11:03:42.000+00:00"
	},
	{
		"film_id": 2,
		"title": "ACE GOLDFINGER",
		"description": "A Astounding Epistle of a Database Administrator And a Explorer who must Find a Car in Ancient China",
		"release_year": "2006-01-01",
		"language_id": 1,
		"original_language_id": null,
		"rental_duration": 3,
		"rental_rate": 4.99,
		"length": 48,
		"replacement_cost": 12.99,
		"rating": "G",
		"special_features": "Trailers,Deleted Scenes",
		"last_update": "2006-02-15T11:03:42.000+00:00"
	},
    ....
]

This query will:

  • fetch all the rows from the table.
  • it will include all the columns from the table.

This is not ideal, if the table has many records as it will result in a full table scan and lot of data transported over the network. It may also result in time-outs. DB2Rest can solve these problems by:

  1. Column filtering - Allowing specifying the names of the columns that should be included in the result-set.
  2. Row filtering - Apply filtering criteria on the table rows to retrieves only the matching rows.
  3. Pagination - Retrieve only a subset of the table rows that match the horizontal filtering. For example, if the row filters match 35 rows and requested page size is 10, then this means 4 pages of rows - where first three pages contain 10 rows and the last one has 5 row. In order to browse through these rows, 4 separate requests have to be made.

The next sections will discuss filtering in greater detail.