Struct Metadata 

pub struct Metadata { /* private fields */ }

Metadata contains the catalog, schema, table, column, and index definitions for a data source.

┌────────────────────────┐
│ CATALOG (database)     │
│ ┌───────────────────┐  │
│ │SCHEMA (namespace) │  │
│ │┌────────┬────────┐│  │
│ ││ TABLE  │ TABLE  ││  │
│ ││ row    │ row    ││  │
│ ││ row    │ row    ││  │
│ ││ row    │ row    ││  │
│ │└────────┴────────┘│  │
│ └───────────────────┘  │
│ ┌───────────────────┐  │
│ │SCHEMA (namespace) │  │
│ │┌────────┬────────┐│  │
│ ││ TABLE  │ TABLE  ││  │
│ ││ row    │ row    ││  │
│ ││ row    │ row    ││  │
│ ││ row    │ row    ││  │
│ │└────────┴────────┘│  │
│ └───────────────────┘  │
└────────────────────────┘

┌───────────────────────────────────┐
│              TABLE                │
├───────────┬───────────┬───────────┤
│ Column A  │ Column B  │ Column C  │
├───────────┼───────────┼───────────┤
│ Value A1  │ Value B1  │ Value C1  │ ← Row 1
│ Value A2  │ Value B2  │ Value C2  │ ← Row 2
│ Value A3  │ Value B3  │ Value C3  │ ← Row 3
│     ⋮     │     ⋮     │     ⋮     │
│ Value An  │ Value Bn  │ Value Cn  │ ← Row n
└───────────┴───────────┴───────────┘

Implementations

impl Metadata

pub fn new() -> Metadata

Creates a new Metadata instance.

pub fn with_dialect(dialect: Box<dyn Dialect>) -> Metadata

Creates a new Metadata instance with the specified dialect.

pub fn dialect(&self) -> Box<dyn Dialect>

Returns the dialect for the metadata.

pub fn add(&mut self, catalog: Catalog)

Adds a catalog to the metadata.

pub fn get<S>(&self, name: S) -> Option<&Catalog>

where S: Into<String>,

Returns the catalog with the specified name.

pub fn get_mut<S>(&mut self, name: S) -> Option<&mut Catalog>

where S: Into<String>,

Returns the mutable catalog with the specified name.

pub fn current_catalog(&self) -> Option<&Catalog>

Returns the current catalog.

pub fn catalogs(&self) -> Vec<&Catalog>

Returns the catalogs in the metadata.

pub fn current_catalog_schema(&self) -> Option<&Schema>

Returns the current schema of the current catalog

Trait Implementations

impl Clone for Metadata

fn clone(&self) -> Metadata

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Metadata

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

Formats the value using the given formatter.

impl Default for Metadata

fn default() -> Metadata

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Metadata

fn deserialize<__D>( __deserializer: __D, ) -> Result<Metadata, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Metadata

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.