Struct googapis::google::spanner::v1::KeyRange [−][src]
pub struct KeyRange {
pub start_key_type: Option<StartKeyType>,
pub end_key_type: Option<EndKeyType>,
}
Expand description
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][google.spanner.v1.TypeCode].
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"]
["Alfred", "2015-06-12"]
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.
Fields
start_key_type: Option<StartKeyType>
The start key must be provided. It can be either closed or open.
end_key_type: Option<EndKeyType>
The end key must be provided. It can be either closed or open.
Trait Implementations
fn merge_field<B>(
&mut self,
tag: u32,
wire_type: WireType,
buf: &mut B,
ctx: DecodeContext
) -> Result<(), DecodeError> where
B: Buf,
Returns the encoded length of the message without a length delimiter.
Encodes the message to a buffer. Read more
Encodes the message to a newly allocated buffer.
Encodes the message with a length-delimiter to a buffer. Read more
Encodes the message with a length-delimiter to a newly allocated buffer.
Decodes an instance of the message from a buffer. Read more
fn decode_length_delimited<B>(buf: B) -> Result<Self, DecodeError> where
Self: Default,
B: Buf,
fn decode_length_delimited<B>(buf: B) -> Result<Self, DecodeError> where
Self: Default,
B: Buf,
Decodes a length-delimited instance of the message from the buffer.
Decodes an instance of the message from a buffer, and merges it into self
. Read more
Decodes a length-delimited instance of the message from buffer, and
merges it into self
. Read more
Auto Trait Implementations
impl RefUnwindSafe for KeyRange
impl UnwindSafe for KeyRange
Blanket Implementations
Mutably borrows from an owned value. Read more
Wrap the input message T
in a tonic::Request
pub fn vzip(self) -> V
Attaches the provided Subscriber
to this type, returning a
WithDispatch
wrapper. Read more
Attaches the current default Subscriber
to this type, returning a
WithDispatch
wrapper. Read more