Trait diesel::sql_types::TypeMetadata

pub trait TypeMetadata {
    type TypeMetadata;
    type MetadataLookup: ?Sized;
}

Information about how a backend stores metadata about given SQL types

Required Associated Types

type TypeMetadata

The actual type used to represent metadata.

On PostgreSQL, this is the type’s OID. On MySQL and SQLite, this is an enum representing all storage classes they support.

type MetadataLookup: ?Sized

The type used for runtime lookup of metadata.

For most backends, which don’t support user defined types, this will be ().

Implementors

impl TypeMetadata for Mysql

Available on crate feature mysql_backend only.

type TypeMetadata = MysqlType

type MetadataLookup = ()

impl TypeMetadata for Pg

Available on crate feature postgres_backend only.

type TypeMetadata = PgTypeMetadata

type MetadataLookup = dyn PgMetadataLookup + 'static

impl TypeMetadata for Sqlite

Available on crate feature sqlite only.

type TypeMetadata = SqliteType

type MetadataLookup = ()