Struct SecondaryScan 

pub struct SecondaryScan<PrimaryTable, SecondaryTable, T: ToInput>
where
    PrimaryTable: ReadableTable<Key, &'static [u8]>,
    SecondaryTable: ReadableMultimapTable<Key, Key>,
{ /* private fields */ }

Scan values from the database by secondary key.

Implementations

impl<PrimaryTable, SecondaryTable, T: ToInput> SecondaryScan<PrimaryTable, SecondaryTable, T>

where PrimaryTable: ReadableTable<Key, &'static [u8]>, SecondaryTable: ReadableMultimapTable<Key, Key>,

pub fn all(&self) -> Result<SecondaryScanIterator<'_, PrimaryTable, T>>

Iterate over all values by secondary key.

If the secondary key is optional you will get all values that have the secondary key set.

Anatomy of a secondary key it is a enum with the following structure: <table_name>Key::<name>.

Example

use native_db::*;
use native_model::{native_model, Model};
use serde::{Deserialize, Serialize};
use itertools::Itertools;

#[derive(Serialize, Deserialize)]
#[native_model(id=1, version=1)]
#[native_db]
struct Data {
    #[primary_key]
    id: u64,
    #[secondary_key(optional)]
    name: Option<String>,
}

fn main() -> Result<(), db_type::Error> {
    let mut models = Models::new();
    models.define::<Data>()?;
    let db = Builder::new().create_in_memory(&models)?;
     
    // Open a read transaction
    let r = db.r_transaction()?;
     
    // Get only values that have the secondary key set (name is not None)
    let _values: Vec<Data> = r.scan().secondary(DataKey::name)?.all()?.try_collect()?;
    Ok(())
}

pub fn range<R: RangeBounds<impl ToKey>>( &self, range: R, ) -> Result<SecondaryScanIterator<'_, PrimaryTable, T>>

Iterate over all values by secondary key.

Anatomy of a secondary key it is a enum with the following structure: <table_name>Key::<name>.

Example

use native_db::*;
use native_model::{native_model, Model};
use serde::{Deserialize, Serialize};
use itertools::Itertools;

#[derive(Serialize, Deserialize)]
#[native_model(id=1, version=1)]
#[native_db]
struct Data {
    #[primary_key]
    id: u64,
    #[secondary_key]
    name: String,
}

fn main() -> Result<(), db_type::Error> {
    let mut models = Models::new();
    models.define::<Data>()?;
    let db = Builder::new().create_in_memory(&models)?;
     
    // Open a read transaction
    let r = db.r_transaction()?;
     
    // Get only values that have the secondary key name from C to the end
    let _values: Vec<Data> = r.scan().secondary(DataKey::name)?.range("C"..)?.try_collect()?;
    Ok(())
}

pub fn start_with( &self, start_with: impl ToKey, ) -> Result<SecondaryScanIterator<'_, PrimaryTable, T>>

Iterate over all values by secondary key.

Anatomy of a secondary key it is a enum with the following structure: <table_name>Key::<name>.

Example

use native_db::*;
use native_model::{native_model, Model};
use serde::{Deserialize, Serialize};
use itertools::Itertools;

#[derive(Serialize, Deserialize)]
#[native_model(id=1, version=1)]
#[native_db]
struct Data {
    #[primary_key]
    id: u64,
    #[secondary_key]
    name: String,
}

fn main() -> Result<(), db_type::Error> {
    let mut models = Models::new();
    models.define::<Data>()?;
    let db = Builder::new().create_in_memory(&models)?;
     
    // Open a read transaction
    let r = db.r_transaction()?;
     
    // Get only values that have the secondary key name starting with "hello"
    let _values: Vec<Data> = r.scan().secondary(DataKey::name)?.start_with("hello")?.try_collect()?;
    Ok(())
}