Struct ProjectionBuilder 

pub struct ProjectionBuilder { /* private fields */ }

Implementations

impl ProjectionBuilder

pub fn deep_initialize_from_struct( name: Option<Identifier>, hst: Struct, ) -> Self

Construct a new projection builder with items initialized to reference to the fields in the given struct. Initialize the references to the fields in this struct with the given prefix. The projection builder would be useful to be used to select the given struct by the given name.

pub fn expand_repeated_struct( array: SQLExpression, from: &Type, to: &Type, ) -> Result<SQLExpression, ExpandError>

pub fn expand(&self, to: Struct) -> Result<Self, ExpandError>

Expand this projection builder to entirely cover the given type.

Where this projection builder does not define a column in the given type, it will add a null literal. It will also reorder the columns to match the given.

Arguments

• to - The struct type to expand to

pub fn bind(&mut self, id: Identifier, value: SQLExpression, type_: Type)

Bind a new column value in the list of projections.

Arguments

• id - Bind this column. Compound identifiers are okay here. It will nest!
• value - Bind to this expression
• type - Assume this type. (Needed in order to construct the cast parts of a row literal.)

pub fn with_binding( self, id: Identifier, value: SQLExpression, type_: Type, ) -> Self

Bind a new column value in the list of projections, returning a new projection builder.

Arguments

• id - Bind this column. Compound identifiers are okay here. It will nest!
• value - Bind to this expression
• type - Assume this type. (Needed in order to construct the cast parts of a row literal.)

pub fn bind_all(&self, other: &Self) -> Self

Bind all projections from another projection builder to this one.

It will bind every column in the other projection builder to this one. If a column is present in both, it will be bound to the expression in the other projection builder.

Arguments

• other - The other projection builder to bind the projections from with this one

Returns

The new projection builder containing the bindings from this and the other projection builder

pub fn bind_column_reference(&mut self, ident: SimpleIdentifier, type_: Type)

Bind a new column reference in the list of projections.

Rather than binding a variable to a value, this binds a variable to a self-reference.

Arguments

• ident - Bind this column
• type_ - Assume this type. (Needed in order to construct the cast parts of a row literal.)

pub fn initialize_key(&mut self, ident: SimpleIdentifier, struct_type: Struct)

Initialize a key in the list of projections from a Hamelin struct type. This will set all the expressions to self-reference column references. This is useful when wanting to construct a projection literal after having messed with the environment by removing nested elements.

Arguments

• ident - Initialize this column
• struct_type - Initialize the column to a self-reference literal of this type

pub fn is_present(&self, id: &Identifier) -> bool

Test whether a key is present in the list of projections.

Returns

True if the key is present, false otherwise.

pub fn build_literal(&self) -> RowLiteral

pub fn build_sql_type(&self) -> Result<SQLRowType>

pub fn build_cast(&self) -> Result<Cast>

pub fn build_hamelin_type(self) -> Struct

pub fn build_projections(self) -> Result<Vec<Projection>>

Trait Implementations

impl Clone for ProjectionBuilder

fn clone(&self) -> ProjectionBuilder

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ProjectionBuilder

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

Formats the value using the given formatter.

impl Default for ProjectionBuilder

fn default() -> ProjectionBuilder

Returns the “default value” for a type.