Trait deltalake::datafusion::logical_expr::expr_schema::ExprSchemable

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pub trait ExprSchemable {
    // Required methods
    fn get_type(
        &self,
        schema: &dyn ExprSchema
    ) -> Result<DataType, DataFusionError>;
    fn nullable(
        &self,
        input_schema: &dyn ExprSchema
    ) -> Result<bool, DataFusionError>;
    fn metadata(
        &self,
        schema: &dyn ExprSchema
    ) -> Result<HashMap<String, String>, DataFusionError>;
    fn to_field(
        &self,
        input_schema: &dyn ExprSchema
    ) -> Result<DFField, DataFusionError>;
    fn cast_to(
        self,
        cast_to_type: &DataType,
        schema: &dyn ExprSchema
    ) -> Result<Expr, DataFusionError>;
    fn data_type_and_nullable(
        &self,
        schema: &dyn ExprSchema
    ) -> Result<(DataType, bool), DataFusionError>;
}
Expand description

trait to allow expr to typable with respect to a schema

Required Methods§

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fn get_type(&self, schema: &dyn ExprSchema) -> Result<DataType, DataFusionError>

given a schema, return the type of the expr

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fn nullable( &self, input_schema: &dyn ExprSchema ) -> Result<bool, DataFusionError>

given a schema, return the nullability of the expr

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fn metadata( &self, schema: &dyn ExprSchema ) -> Result<HashMap<String, String>, DataFusionError>

given a schema, return the expr’s optional metadata

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fn to_field( &self, input_schema: &dyn ExprSchema ) -> Result<DFField, DataFusionError>

convert to a field with respect to a schema

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fn cast_to( self, cast_to_type: &DataType, schema: &dyn ExprSchema ) -> Result<Expr, DataFusionError>

cast to a type with respect to a schema

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fn data_type_and_nullable( &self, schema: &dyn ExprSchema ) -> Result<(DataType, bool), DataFusionError>

given a schema, return the type and nullability of the expr

Implementors§