Struct Query 

pub struct Query {
    pub with: Option<With>,
    pub body: ExprSet,
    pub single: bool,
    pub order_by: Option<OrderBy>,
    pub limit: Option<Limit>,
    pub locks: Vec<Lock>,
}

A query statement that reads data from the database.

Query wraps a set expression body (typically a Select) with optional ordering, limits, CTEs, and row-level locks. It is the read-side counterpart to [Insert], Update, and Delete.

Examples

use toasty_core::stmt::{Query, Values, ExprSet};

// A unit query that returns one empty row
let q = Query::unit();
assert!(matches!(q.body, ExprSet::Values(_)));
assert!(!q.single);

Fields

with: Option<With>

Optional common table expressions (CTEs) for this query.

body: ExprSet

The body of the query. Either SELECT, UNION, VALUES, or possibly other types of queries depending on database support.

single: bool

When true, the query returns a single record instead of a list.

This is semantically different from LIMIT 1: it indicates there can only ever be one matching result. The return type becomes Record instead of List.

order_by: Option<OrderBy>

Optional ORDER BY clause.

limit: Option<Limit>

Optional LIMIT and OFFSET clause.

locks: Vec<Lock>

Row-level locks (FOR UPDATE, FOR SHARE).

Implementations

impl Query

pub fn filter(&self) -> Option<&Filter>

Returns a reference to this query’s filter if the body is a SELECT.

pub fn filter_unwrap(&self) -> &Filter

Returns a reference to this query’s filter.

Panics

Panics if the query body is not a SELECT.

pub fn filter_mut(&mut self) -> Option<&mut Filter>

Returns a mutable reference to the query’s filter.

Returns None for queries that are not SELECT statements, such as UNION or VALUES.

pub fn filter_mut_unwrap(&mut self) -> &mut Filter

Returns a mutable reference to the query’s filter.

Panics

Panics if the query body is not a SELECT statement.

impl Query

pub fn new(body: impl Into<ExprSet>) -> Query

Creates a new query with the given body and default options (no ordering, no limit, not single, no locks).

pub fn new_single(body: impl Into<ExprSet>) -> Query

Creates a new query that returns exactly one record (single = true).

pub fn new_select(source: impl Into<Source>, filter: impl Into<Filter>) -> Query

Creates a new SELECT query from a source and filter.

pub fn builder(body: impl Into<ExprSet>) -> QueryBuilder

Returns a [QueryBuilder] initialized with the given body.

pub fn unit() -> Query

Creates a unit query that produces one empty row (empty VALUES).

pub fn values(values: impl Into<Values>) -> Query

Creates a query whose body is a VALUES expression.

pub fn update(self) -> Update

Converts this query into an Update statement targeting the same source. The query must have a SELECT body with a model source.

pub fn delete(self) -> Delete

Converts this query into a Delete statement. The query body must be a SELECT.

pub fn add_filter(&mut self, filter: impl Into<Filter>)

Adds a filter to this query’s SELECT body.

Panics

Panics if the query body is not a SELECT.

pub fn include(&mut self, path: impl Into<Path>)

Adds an association include path to this query’s SELECT body.

impl Query

pub fn returning(&self) -> Option<&Returning>

Returns a reference to this query’s RETURNING clause, if present.

Returns Some only for SELECT queries. Other query types (VALUES, UNION, etc.) do not have a RETURNING clause.

pub fn returning_unwrap(&self) -> &Returning

Returns a reference to this query’s RETURNING clause.

Panics

Panics if the query does not have a RETURNING clause (i.e., the body is not a SELECT).

pub fn returning_mut(&mut self) -> Option<&mut Returning>

Returns a mutable reference to this query’s RETURNING clause, if present.

Returns Some only for SELECT queries. Other query types (VALUES, UNION, etc.) do not have a RETURNING clause.

pub fn returning_mut_unwrap(&mut self) -> &mut Returning

Returns a mutable reference to this query’s RETURNING clause.

Panics

Panics if the query does not have a RETURNING clause (i.e., the body is not a SELECT).

impl Query

pub fn into_select(self) -> Select

Consumes this query and returns the inner Select.

Panics

Panics if the query body is not a SELECT.

Trait Implementations

impl Clone for Query

fn clone(&self) -> Query

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Query

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

Formats the value using the given formatter.

impl From<Query> for InsertTarget

fn from(value: Query) -> InsertTarget

Converts to this type from the input type.

impl From<QueryBuilder> for Query

fn from(value: QueryBuilder) -> Query

Converts to this type from the input type.

impl From<Select> for Query

fn from(value: Select) -> Query

Converts to this type from the input type.

impl From<Values> for Query

fn from(value: Values) -> Query

Converts to this type from the input type.

impl<'a, T> IntoExprTarget<'a, T> for &'a Query

where T: Resolve,

fn into_expr_target(self, schema: &'a T) -> ExprTarget<'a>

Converts self into an ExprTarget using the provided schema.

impl Node for Query

fn visit<V>(&self, visit: V)

where V: Visit,

Traverses this node with an immutable visitor.

fn visit_mut<V>(&mut self, visit: V)

where V: VisitMut,

Traverses this node with a mutable visitor.

impl PartialEq for Query

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Query