KeyRange
import type { KeyRange } from "https://googleapis.deno.dev/v1/spanner:v1.ts";
KeyRange represents a range of rows in a table or index. A range has a start
key and an end key. These keys can be open or closed, indicating if the range
includes rows with that key. Keys are represented by lists, where the ith
value in the list corresponds to the ith component of the table or index
primary key. Individual values are encoded as described here. For example,
consider the following table definition: CREATE TABLE UserEvents ( UserName
STRING(MAX), EventDate STRING(10) ) PRIMARY KEY(UserName, EventDate); The
following keys name rows in this table: "Bob", "2014-09-23" Since the
UserEvents
table's PRIMARY KEY
clause names two columns, each
UserEvents
key has two elements; the first is the UserName
, and the
second is the EventDate
. Key ranges with multiple components are
interpreted lexicographically by component using the table or index key's
declared sort order. For example, the following range returns all events for
user "Bob"
that occurred in the year 2015: "start_closed": ["Bob",
"2015-01-01"] "end_closed": ["Bob", "2015-12-31"] Start and end keys can omit
trailing key components. This affects the inclusion and exclusion of rows
that exactly match the provided key components: if the key is closed, then
rows that exactly match the provided components are included; if the key is
open, then rows that exactly match are not included. For example, the
following range includes all events for "Bob"
that occurred during and
after the year 2000: "start_closed": ["Bob", "2000-01-01"] "end_closed":
["Bob"] The next example retrieves all events for "Bob"
: "start_closed":
["Bob"] "end_closed": ["Bob"] To retrieve events before the year 2000:
"start_closed": ["Bob"] "end_open": ["Bob", "2000-01-01"] The following range
includes all rows in the table: "start_closed": [] "end_closed": [] This
range returns all users whose UserName
begins with any character from A to
C: "start_closed": ["A"] "end_open": ["D"] This range returns all users whose
UserName
begins with B: "start_closed": ["B"] "end_open": ["C"] Key ranges
honor column sort order. For example, suppose a table is defined as follows:
CREATE TABLE DescendingSortedTable { Key INT64, ... ) PRIMARY KEY(Key DESC);
The following range retrieves all rows with key values between 1 and 100
inclusive: "start_closed": ["100"] "end_closed": ["1"] Note that 100 is
passed as the start, and 1 is passed as the end, because Key
is a
descending column in the schema.
§Properties
If the end is closed, then the range includes all rows whose first
len(end_closed)
key columns exactly match end_closed
.
If the end is open, then the range excludes rows whose first
len(end_open)
key columns exactly match end_open
.