Struct google_cloud_spanner::key::Key

pub struct Key { /* fields omitted */ }

A Key can be either a Cloud Spanner row’s primary key or a secondary index key. A Key can be used as:

• A primary key which uniquely identifies a Cloud Spanner row.
• A secondary index key which maps to a set of Cloud Spanner rows indexed under it.
• An endpoint of primary key/secondary index ranges; see the KeyRange type.

Rows that are identified by the Key type are outputs of read operation or targets of delete operation in a mutation. Note that for insert/update/insert_or_update/delete mutation types, although they don’t require a primary key explicitly, the column list provided must contain enough columns that can comprise a primary key.

Keys are easy to construct. For example, suppose you have a table with a primary key of username and product ID. To make a key for this table:

use google_cloud_spanner::key::Key;

let key = Key::composite(&[&"john", &16]);

See the description of Row and Mutation types for how Go types are mapped to Cloud Spanner types. For convenience, Key type supports a range of Rust types:

• i64 and Option are mapped to Cloud Spanner’s INT64 type.
• f64 and Option are mapped to Cloud Spanner’s FLOAT64 type.
• bool and Option are mapped to Cloud Spanner’s BOOL type.
• Vec, &u8, Option<Vec> and Option<&u8> is mapped to Cloud Spanner’s BYTES type.
• String, &str, Option, Option<&str> are mapped to Cloud Spanner’s STRING type.
• chrono::NaiveDateTime and Optionchrono::NaiveDateTime are mapped to Cloud Spanner’s TIMESTAMP type.
• chrono::DateTime and Optionchrono::DateTime are mapped to Cloud Spanner’s DATE type.
• google_cloud_spanner::value::CommitTimestamp and Option<google_cloud_spanner::value::CommitTimestamp> are mapped to Cloud Spanner’s TIMESTAMP type.

Implementations

impl Key

pub fn key(value: &dyn ToKind) -> Key

one creates new Key

Examples

   use google_cloud_spanner::key::Key;
   use google_cloud_spanner::statement::ToKind;
   let key1 = Key::key(&"a");
   let key2 = Key::key(&1);

pub fn composite(values: &[&dyn ToKind]) -> Key

one creates new Key

Examples

   use google_cloud_spanner::key::Key;
   use google_cloud_spanner::statement::ToKind;
   let multi_key = Key::composite(&[&"a", &1]);

Trait Implementations

impl Clone for Key

fn clone(&self) -> Key

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl From<Key> for KeySet

fn from(key: Key) -> Self

Performs the conversion.