Struct datafusion_common::DFSchema

pub struct DFSchema { /* private fields */ }

DFSchema wraps an Arrow schema and adds relation names

Implementations

impl DFSchema

pub fn empty() -> Self

Creates an empty DFSchema

pub fn new(fields: Vec<DFField>) -> Result<Self>

👎Deprecated since 7.0.0: please use new_with_metadata instead

Create a new DFSchema

pub fn new_with_metadata( fields: Vec<DFField>, metadata: HashMap<String, String> ) -> Result<Self>

Create a new DFSchema

pub fn try_from_qualified_schema<'a>( qualifier: impl Into<TableReference<'a>>, schema: &Schema ) -> Result<Self>

Create a DFSchema from an Arrow schema and a given qualifier

pub fn with_functional_dependencies( self, functional_dependencies: FunctionalDependencies ) -> Self

Assigns functional dependencies.

pub fn join(&self, schema: &DFSchema) -> Result<Self>

Create a new schema that contains the fields from this schema followed by the fields from the supplied schema. An error will be returned if there are duplicate field names.

pub fn merge(&mut self, other_schema: &DFSchema)

Modify this schema by appending the fields from the supplied schema, ignoring any duplicate fields.

pub fn fields(&self) -> &Vec<DFField>

Get a list of fields

pub fn field(&self, i: usize) -> &DFField

Returns an immutable reference of a specific Field instance selected using an offset within the internal fields vector

pub fn index_of(&self, name: &str) -> Result<usize>

👎Deprecated since 8.0.0: please use index_of_column_by_name instead

Find the index of the column with the given unqualified name

pub fn index_of_column_by_name( &self, qualifier: Option<&TableReference<'_>>, name: &str ) -> Result<Option<usize>>

pub fn index_of_column(&self, col: &Column) -> Result<usize>

Find the index of the column with the given qualifier and name

pub fn is_column_from_schema(&self, col: &Column) -> Result<bool>

Check if the column is in the current schema

pub fn field_with_name( &self, qualifier: Option<&TableReference<'_>>, name: &str ) -> Result<&DFField>

Find the field with the given name

pub fn fields_with_qualified( &self, qualifier: &TableReference<'_> ) -> Vec<&DFField>

Find all fields having the given qualifier

pub fn fields_with_unqualified_name(&self, name: &str) -> Vec<&DFField>

Find all fields match the given name

pub fn field_with_unqualified_name(&self, name: &str) -> Result<&DFField>

Find the field with the given name

pub fn field_with_qualified_name( &self, qualifier: &TableReference<'_>, name: &str ) -> Result<&DFField>

Find the field with the given qualified name

pub fn field_from_column(&self, column: &Column) -> Result<&DFField>

Find the field with the given qualified column

pub fn has_column_with_unqualified_name(&self, name: &str) -> bool

Find if the field exists with the given name

pub fn has_column_with_qualified_name( &self, qualifier: &TableReference<'_>, name: &str ) -> bool

Find if the field exists with the given qualified name

pub fn has_column(&self, column: &Column) -> bool

Find if the field exists with the given qualified column

pub fn matches_arrow_schema(&self, arrow_schema: &Schema) -> bool

Check to see if unqualified field names matches field names in Arrow schema

pub fn check_arrow_schema_type_compatible( &self, arrow_schema: &Schema ) -> Result<()>

Check to see if fields in 2 Arrow schemas are compatible

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

Returns true if the two schemas have the same qualified named fields with the same data types. Returns false otherwise.

This is a specialized version of Eq that ignores differences in nullability and metadata.

pub fn strip_qualifiers(self) -> Self

Strip all field qualifier in schema

pub fn replace_qualifier( self, qualifier: impl Into<OwnedTableReference> ) -> Self

Replace all field qualifier with new value in schema

pub fn field_names(&self) -> Vec<String>

Get list of fully-qualified field names in this schema

pub fn metadata(&self) -> &HashMap<String, String>

Get metadata of this schema

pub fn functional_dependencies(&self) -> &FunctionalDependencies

Get functional dependencies

Trait Implementations

impl Clone for DFSchema

fn clone(&self) -> DFSchema

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for DFSchema

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

Formats the value using the given formatter.

impl Display for DFSchema

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

Formats the value using the given formatter.

impl ExprSchema for DFSchema

fn nullable(&self, col: &Column) -> Result<bool>

Is this column reference nullable?

fn data_type(&self, col: &Column) -> Result<&DataType>

What is the datatype of this column?

fn metadata(&self, col: &Column) -> Result<&HashMap<String, String>>

Returns the column’s optional metadata.

impl From<&DFSchema> for Schema

fn from(df_schema: &DFSchema) -> Self

Convert DFSchema reference into a Schema

impl From<DFSchema> for Schema

fn from(df_schema: DFSchema) -> Self

Convert DFSchema into a Schema

impl From<DFSchema> for SchemaRef

fn from(df_schema: DFSchema) -> Self

Converts to this type from the input type.

impl Hash for DFSchema

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq<DFSchema> for DFSchema

fn eq(&self, other: &DFSchema) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl TryFrom<Schema> for DFSchema

Create a DFSchema from an Arrow schema

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(schema: Schema) -> Result<Self, Self::Error>

Performs the conversion.

impl Eq for DFSchema

impl StructuralEq for DFSchema

impl StructuralPartialEq for DFSchema