Object ID functions

An object id function creates or converts an OID value of CamusDB. These functions are useful in a primary key, in an insert, in a filter, and in a query with a parameter.

Function	Returns	Description
`gen_id()`	`OID`	It generates a new object id. The function is volatile.
`to_id(value)`	`OID`	It converts an `OID` to an object id. It also converts a hexadecimal string of 24 lowercase characters.
`str_id(value)`	`OID`	An alias of `to_id(value)`.

Examples

CREATE TABLE robots (
  id OID PRIMARY KEY NOT NULL DEFAULT (gen_id()),
  name STRING NOT NULL
);

INSERT INTO robots (name)
VALUES ("R2-D2");

INSERT INTO robots (id, name)
VALUES (gen_id(), "BB-8");

SELECT id, name
FROM robots
WHERE id = str_id("507f1f77bcf86cd799439011");

SELECT to_id(@id)
FROM robots
LIMIT 1;

gen_id() returns a string of an object id, with 24 characters.

DEFAULT (gen_id()) on an OID column runs one time for each inserted row. An omitted id and a DEFAULT value therefore both receive their own ObjectId.

to_id and str_id accept an existing OID value. They also accept a string of exactly 24 lowercase hexadecimal characters.

For the full rules of a conversion, see Conversion Functions.

Examples​

Examples