Trait Fields

pub trait Fields {
    const PRIMARY_KEY: Option<&'static [usize]>;

    // Required methods
    fn fields() -> Vec<(&'static str, DataType)>;
    fn into_owned_row(self) -> OwnedRow;

    // Provided method
    fn data_chunk_builder(capacity: usize) -> DataChunkBuilder { ... }
}

A struct can implements Fields when if can be represented as a relational Row.

Derivable

This trait can be automatically derived with #[derive(Fields)]. Type of the fields must implement WithDataType and ToOwnedDatum.

#[derive(Fields)]
struct Data {
    v1: i16,
    v2: i32,
}

You can add #[primary_key] attribute to one of the fields to specify the primary key of the table.

#[derive(Fields)]
struct Data {
    #[primary_key]
    v1: i16,
    v2: i32,
}

If the primary key is composite, you can add #[primary_key(...)] attribute to the struct to specify the order of the fields.

#[derive(Fields)]
#[primary_key(v2, v1)]
struct Data {
    v1: i16,
    v2: i32,
}

Required Associated Constants

const PRIMARY_KEY: Option<&'static [usize]>

The primary key of the table.

• None if the primary key is not applicable.
• Some(&[]) if the primary key is empty, i.e., there’ll be at most one row in the table.

Required Methods

fn fields() -> Vec<(&'static str, DataType)>

Return the schema of the struct.

fn into_owned_row(self) -> OwnedRow

Convert the struct to an OwnedRow.

Provided Methods

fn data_chunk_builder(capacity: usize) -> DataChunkBuilder

Create a DataChunkBuilder with the schema of the struct.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors