Struct Query

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pub struct Query {
    pub selection: Arc<BTreeMap<String, Vec<TableSelection>>>,
    pub fields: BTreeMap<String, Vec<String>>,
}

Expand description

A query definition specifying which rows and columns to return from a set of tables.

selection defines per-table row filters and cross-table join rules. fields defines which columns to project for each table.

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§selection: Arc<BTreeMap<String, Vec<TableSelection>>>

Row selection rules keyed by table name. Multiple TableSelections for the same table are OR-combined (a row passes if it matches any selection).

§fields: BTreeMap<String, Vec<String>>

Columns to include in the output, keyed by table name.

Implementations§

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impl Query

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pub fn add_request_and_include_fields(&mut self) -> Result<()>

Adds all filter and include column names to self.fields so that they are present in the projected output. This ensures columns referenced by filters and joins are fetched from the data source.

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impl Clone for Query

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fn clone(&self) -> Query

Returns a duplicate of the value. Read more

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

Performs copy-assignment from source. Read more

Auto Trait Implementations§

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impl !UnwindSafe for Query

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

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impl<T> CloneToUninit for T
where T: Clone,

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unsafe fn clone_to_uninit(&self, dest: *mut u8)

🔬This is a nightly-only experimental API. (clone_to_uninit)

Performs copy-assignment from self to dest. Read more

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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> IntoEither for T

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fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more

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fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more

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