using System;
using Npgsql.Internal.Postgres;
namespace Npgsql.PostgresTypes;
///
/// Represents a PostgreSQL data type, such as int4 or text, as discovered from pg_type.
/// This class is abstract, see derived classes for concrete types of PostgreSQL types.
///
///
/// Instances of this class are shared between connections to the same databases.
/// For more info about what this class and its subclasses represent, see
/// https://www.postgresql.org/docs/current/static/catalog-pg-type.html.
///
public abstract class PostgresType
{
#region Constructors
///
/// Constructs a representation of a PostgreSQL data type.
///
/// The data type's namespace (or schema).
/// The data type's name.
/// The data type's OID.
private protected PostgresType(string ns, string name, uint oid)
{
DataTypeName = DataTypeName.FromDisplayName(name, ns, assumeUnqualified: true);
OID = oid;
FullName = Namespace + "." + Name;
}
///
/// Constructs a representation of a PostgreSQL data type.
///
/// The data type's fully qualified name.
/// The data type's OID.
private protected PostgresType(DataTypeName dataTypeName, Oid oid)
{
DataTypeName = dataTypeName;
OID = oid.Value;
FullName = Namespace + "." + Name;
}
#endregion
#region Public Properties
///
/// The data type's OID - a unique id identifying the data type in a given database (in pg_type).
///
public uint OID { get; }
///
/// The data type's namespace (or schema).
///
public string Namespace => DataTypeName.Schema;
///
/// The data type's name.
///
///
/// Note that this is the standard, user-displayable type name (e.g. integer[]) rather than the internal
/// PostgreSQL name as it is in pg_type (_int4). See for the latter.
///
public string Name => DataTypeName.UnqualifiedDisplayName;
///
/// The full name of the backend type, including its namespace.
///
public string FullName { get; }
internal DataTypeName DataTypeName { get; }
///
/// A display name for this backend type, including the namespace unless it is pg_catalog (the namespace
/// for all built-in types).
///
public string DisplayName => DataTypeName.DisplayName;
///
/// The data type's internal PostgreSQL name (e.g. _int4 not integer[]).
/// See for a more user-friendly name.
///
public string InternalName => DataTypeName.UnqualifiedName;
///
/// If a PostgreSQL array type exists for this type, it will be referenced here.
/// Otherwise null.
///
public PostgresArrayType? Array { get; internal set; }
///
/// If a PostgreSQL range type exists for this type, it will be referenced here.
/// Otherwise null.
///
public PostgresRangeType? Range { get; internal set; }
#endregion
internal virtual string GetPartialNameWithFacets(int typeModifier) => Name;
///
/// Generates the type name including any facts (size, precision, scale), given the PostgreSQL type modifier.
///
internal string GetDisplayNameWithFacets(int typeModifier)
=> Namespace == "pg_catalog"
? GetPartialNameWithFacets(typeModifier)
: Namespace + '.' + GetPartialNameWithFacets(typeModifier);
internal virtual PostgresFacets GetFacets(int typeModifier) => PostgresFacets.None;
///
/// Returns a string that represents the current object.
///
public override string ToString() => DisplayName;
PostgresType? _representationalType;
/// Canonizes (nested) domain types to underlying types, does not handle composites.
internal PostgresType GetRepresentationalType()
{
return _representationalType ??= Core(this) ?? throw new InvalidOperationException("Couldn't map type to representational type");
static PostgresType? Core(PostgresType? postgresType)
=> (postgresType as PostgresDomainType)?.BaseType ?? postgresType switch
{
PostgresArrayType { Element: PostgresDomainType domain } => Core(domain.BaseType)?.Array,
PostgresMultirangeType { Subrange.Subtype: PostgresDomainType domain } => domain.BaseType.Range?.Multirange,
PostgresRangeType { Subtype: PostgresDomainType domain } => domain.Range,
var type => type
};
}
}