Struct DataSet 

pub struct DataSet {
    pub col_names: Vec<String>,
    pub rows: Vec<Vec<Value>>,
}

Simple dataset representation

DataSet is the primary carrier of structured data in query execution, used for passing data between executors and returning results to API layer.

Fields

col_names: Vec<String>

rows: Vec<Vec<Value>>

Implementations

impl DataSet

pub fn new() -> DataSet

pub fn with_columns(col_names: Vec<String>) -> DataSet

Create a DataSet with column names

pub fn from_rows(rows: Vec<Vec<Value>>, col_names: Vec<String>) -> DataSet

Create a DataSet from rows and column names

pub fn add_row(&mut self, row: Vec<Value>)

Add a row

pub fn row_count(&self) -> usize

Get row count

pub fn col_count(&self) -> usize

Get column count

pub fn is_empty(&self) -> bool

Check if empty

pub fn get_col_index(&self, col_name: &str) -> Option<usize>

Get index of specified column

pub fn get_column(&self, col_name: &str) -> Option<Vec<Value>>

Get all values of specified column

pub fn filter<F>(&self, predicate: F) -> DataSet

where F: Fn(&Vec<Value>) -> bool,

Filter dataset

pub fn map<F>(&self, mapper: F) -> DataSet

where F: Fn(&Vec<Value>) -> Vec<Value>,

Map dataset

pub fn sort_by<F>(&mut self, comparator: F)

where F: Fn(&Vec<Value>, &Vec<Value>) -> Ordering,

Sort dataset

pub fn join(&self, other: &DataSet, on: &str) -> Result<DataSet, String>

Join two datasets

pub fn group_by<F, K>(&self, key_fn: F) -> Vec<(K, DataSet)>

where F: Fn(&Vec<Value>) -> K, K: Hash + Eq + Clone,

Group dataset

pub fn aggregate<F, R>(&self, aggregator: F) -> Vec<R>

where F: Fn(&Vec<Value>) -> R,

Aggregate dataset

pub fn limit(&self, n: usize) -> DataSet

Limit rows

pub fn skip(&self, n: usize) -> DataSet

Skip rows

pub fn union(&self, other: &DataSet) -> Result<DataSet, String>

Merge datasets

pub fn intersect(&self, other: &DataSet) -> DataSet

Calculate intersection

pub fn except(&self, other: &DataSet) -> DataSet

Calculate difference

pub fn transpose(&self) -> DataSet

Transpose dataset

pub fn distinct(&self, col_name: &str) -> Vec<Value>

Get unique values

pub fn estimated_size(&self) -> usize

Estimate memory usage

Trait Implementations

impl Clone for DataSet

fn clone(&self) -> DataSet

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DataSet

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for DataSet

fn default() -> DataSet

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for DataSet

fn deserialize<__D>( __deserializer: __D, ) -> Result<DataSet, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Hash for DataSet

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl IntoExecutionResult for DataSet

fn into_execution_result(self) -> ExecutionResult

impl PartialEq for DataSet

fn eq(&self, other: &DataSet) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for DataSet

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for DataSet