Struct ColumnDefault 

pub struct ColumnDefault<'a> { /* private fields */ }

Available on crate feature column-defaults-in-dev only.

A column-level default parsed from the CURRENT_DEFAULT metadata key of a StructField.

Holds the raw SQL and the column’s declared type. On construction the kernel parses the SQL with its built-in parser and caches the result. to_scalar returns the parsed Scalar, or None when the kernel could not parse the SQL (e.g. current_timestamp()), in which case a connector can evaluate raw_sql itself.

The declared type is borrowed from the logical schema, which outlives the carrier.

Implementations

impl<'a> ColumnDefault<'a>

pub fn raw_sql(&self) -> &str

The raw SQL expression as stored in the column’s metadata.

pub fn data_type(&self) -> &DataType

The declared type of the column whose default this is.

pub fn to_scalar(&self) -> DeltaResult<Option<Scalar>>

The default as a Scalar, or None when the kernel could not parse the SQL.

On None the connector can evaluate raw_sql with its own SQL engine.

Errors

Returns an error if the parsed default is not a literal. The parser only emits literals, so this is defensive.

Trait Implementations

impl<'a> Clone for ColumnDefault<'a>

fn clone(&self) -> ColumnDefault<'a>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Debug for ColumnDefault<'a>

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

Formats the value using the given formatter.

impl<'a> PartialEq for ColumnDefault<'a>

fn eq(&self, other: &ColumnDefault<'a>) -> bool

Equality operator ==.

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

Inequality operator !=.

impl<'a> StructuralPartialEq for ColumnDefault<'a>