Struct diesel_dynamic_schema::DynamicSelectClause

pub struct DynamicSelectClause<'a, DB, QS> { /* private fields */ }

Represents a dynamically sized select clause

Implementations

impl<'a, DB, QS> DynamicSelectClause<'a, DB, QS>

pub fn new() -> Self

Constructs a new dynamically sized select clause without any fields

pub fn add_field<F>(&mut self, field: F)where F: QueryFragment<DB> + SelectableExpression<QS> + NonAggregate + Send + 'a, DB: Backend,

Adds the field to the dynamically sized select clause

Trait Implementations

impl<'a, DB, QS> Default for DynamicSelectClause<'a, DB, QS>

fn default() -> Self

Returns the “default value” for a type.

impl<'a, QS, DB> Expression for DynamicSelectClause<'a, DB, QS>

type SqlType = Untyped

The type that this expression represents in SQL

impl<'a, DB, QS> QueryFragment<DB, NotSpecialized> for DynamicSelectClause<'a, DB, QS>where DB: Backend,

fn walk_ast<'b>(&'b self, pass: AstPass<'_, 'b, DB>) -> QueryResult<()>

Walk over this QueryFragment for all passes.

fn to_sql( &self, out: &mut <DB as Backend>::QueryBuilder, backend: &DB ) -> Result<(), Error>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

Converts this QueryFragment to its SQL representation.

fn collect_binds<'b>( &'b self, out: &mut <DB as HasBindCollector<'b>>::BindCollector, metadata_lookup: &mut <DB as TypeMetadata>::MetadataLookup, backend: &'b DB ) -> Result<(), Error>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

Serializes all bind parameters in this query.

fn is_safe_to_cache_prepared(&self, backend: &DB) -> Result<bool, Error>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

Is this query safe to store in the prepared statement cache?

fn is_noop(&self, backend: &DB) -> Result<bool, Error>

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

Does walking this AST have any effect?

impl<'a, DB, QS> QueryId for DynamicSelectClause<'a, DB, QS>

const HAS_STATIC_QUERY_ID: bool = false

Can the SQL generated by Self be uniquely identified by its type?

type QueryId = ()

A type which uniquely represents Self in a SQL query.

fn query_id() -> Option<TypeId>

Returns the type id of Self::QueryId if Self::HAS_STATIC_QUERY_ID. Returns None otherwise.

impl<'a, DB, QS> ValidGrouping<()> for DynamicSelectClause<'a, DB, QS>

type IsAggregate = No

Is this expression aggregate?

impl<'a, DB, QS> AppearsOnTable<QS> for DynamicSelectClause<'a, DB, QS>where Self: Expression,

impl<'a, DB, QS> SelectableExpression<QS> for DynamicSelectClause<'a, DB, QS>where Self: AppearsOnTable<QS>,