Struct QueryColumns 

pub struct QueryColumns { /* private fields */ }

A query result as columns, in the order the query selected them.

Implementations

impl QueryColumns

pub fn new() -> Self

An empty result with no columns.

pub fn with_names<I, S>(names: I, row_capacity: usize) -> Self

where I: IntoIterator<Item = S>, S: Into<String>,

Build empty columns for names, in order, each sized for row_capacity values.

Callers then fill them positionally with push_value, which is what ties a value to the column the driver read it from.

pub fn push_value(&mut self, index: usize, value: String)

Append a value to the column at index.

Out-of-range indices are ignored; callers iterate the same column list they built the result from, so there is no in-range/out-of-range decision for them to get wrong.

pub fn len(&self) -> usize

Number of columns.

pub fn is_empty(&self) -> bool

Whether the result has no columns.

pub fn row_count(&self) -> usize

Rows in the result, read off the first column.

pub fn names(&self) -> impl Iterator<Item = &str>

Column names, in query order.

pub fn values(&self) -> impl Iterator<Item = &Vec<String>>

Column data, in query order.

pub fn iter(&self) -> impl Iterator<Item = (&str, &Vec<String>)>

Name/data pairs, in query order.

pub fn values_mut(&mut self) -> impl Iterator<Item = &mut Vec<String>>

Mutable column data, in query order.

pub fn get(&self, name: &str) -> Option<&Vec<String>>

The data for name, if the result has such a column.

pub fn into_map(self) -> HashMap<String, Vec<String>>

Drop the order and hand back a plain map.

For consumers keyed purely by name — quality metrics look every column up by name and never iterate for presentation.

Trait Implementations

impl Clone for QueryColumns

fn clone(&self) -> QueryColumns

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for QueryColumns

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

Formats the value using the given formatter.

impl Default for QueryColumns

fn default() -> QueryColumns

Returns the “default value” for a type.

impl Eq for QueryColumns

impl FromIterator<(String, Vec<String>)> for QueryColumns

fn from_iter<I: IntoIterator<Item = (String, Vec<String>)>>(iter: I) -> Self

Creates a value from an iterator.

impl Index<&str> for QueryColumns

type Output = Vec<String>

The returned type after indexing.

fn index(&self, name: &str) -> &Self::Output

Performs the indexing (container[index]) operation.

impl IntoIterator for QueryColumns

type Item = (String, Vec<String>)

The type of the elements being iterated over.

type IntoIter = IntoIter<(String, Vec<String>)>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl PartialEq for QueryColumns

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for QueryColumns