Struct StructType

pub struct StructType {
    pub type_name: String,
    pub fields: IndexMap<String, StructField>,
}

A struct is used to represent both the top-level schema of the table as well as struct columns that contain nested columns.

Fields

type_name: String

fields: IndexMap<String, StructField>

The type of element stored in this array

Implementations

impl StructType

pub fn new(fields: impl IntoIterator<Item = StructField>) -> Self

pub fn try_new<E>( fields: impl IntoIterator<Item = Result<StructField, E>>, ) -> Result<Self, E>

pub fn project_as_struct( &self, names: &[impl AsRef<str>], ) -> DeltaResult<StructType>

Get a StructType containing StructFields of the given names. The order of fields in the returned schema will match the order passed to this function, which can be different from this order in this schema. Returns an Err if a specified field doesn’t exist.

pub fn project(&self, names: &[impl AsRef<str>]) -> DeltaResult<SchemaRef>

Get a SchemaRef containing StructFields of the given names. The order of fields in the returned schema will match the order passed to this function, which can be different from this order in this schema. Returns an Err if a specified field doesn’t exist.

pub fn field(&self, name: impl AsRef<str>) -> Option<&StructField>

pub fn index_of(&self, name: impl AsRef<str>) -> Option<usize>

pub fn fields(&self) -> impl Iterator<Item = &StructField>

pub fn leaves<'s>( &self, own_name: impl Into<Option<&'s str>>, ) -> ColumnNamesAndTypes

Available on crate feature internal-api only.

Extracts the name and type of all leaf columns, in schema order. Caller should pass Some own_name if this schema is embedded in a larger struct (e.g. add.*) and None if the schema is a top-level result (e.g. *).

NOTE: This method only traverses through StructType fields; MapType and ArrayType fields are considered leaves even if they contain StructType entries/elements.

pub fn make_physical(&self, column_mapping_mode: ColumnMappingMode) -> Self

Available on crate feature internal-api only.

Applies physical name mappings to this field. If the column_mapping_mode is ColumnMappingMode::Id, then each StructField will have its parquet field id in the ColumnMetadataKey::ParquetFieldId metadata field.

NOTE: Caller affirms that the schema was already validated by crate::table_features::validate_schema_column_mapping, to ensure that annotations are always and only present when column mapping mode is enabled.

Trait Implementations

impl Clone for StructType

fn clone(&self) -> StructType

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for StructType

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for StructType

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>, Self: Sized,

Deserialize this value from the given Serde deserializer.

impl From<StructType> for DataType

fn from(struct_type: StructType) -> Self

Converts to this type from the input type.

impl PartialEq for StructType

fn eq(&self, other: &StructType) -> 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 Serialize for StructType

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl TryFromArrow<&Schema> for StructType

Available on crate feature arrow-conversion and (crate features default-engine or arrow-conversion) only.

fn try_from_arrow(arrow_schema: &ArrowSchema) -> Result<Self, ArrowError>

impl TryFromArrow<Arc<Schema>> for StructType

Available on crate feature arrow-conversion and (crate features default-engine or arrow-conversion) only.

fn try_from_arrow(arrow_schema: ArrowSchemaRef) -> Result<Self, ArrowError>

impl TryFromKernel<&StructType> for Schema

Available on crate feature arrow-conversion and (crate features default-engine or arrow-conversion) only.

fn try_from_kernel(s: &StructType) -> Result<Self, ArrowError>

impl Eq for StructType

impl StructuralPartialEq for StructType