Enum PgError 

#[non_exhaustive]
pub enum PgError {
    Server(Box<PgServerError>),
    Protocol(ProtocolError),
    Transport(TransportError),
    Auth(String),
    TypeConversion(Error),
    Config(String),
    ConnectionClosed,
    UnexpectedNull {
        column: String,
    },
    ColumnNotFound {
        name: String,
    },
    ColumnIndexOutOfBounds {
        index: usize,
        count: usize,
    },
    Timeout,
    Pool(PoolErrorVariant),
    InvalidState(String),
    Unsupported(String),
    Cancelled,
    Io(Error),
    Tls(Error),
    Other(String),
}

The main error type for the PostgreSQL client.

This enum distinguishes between different error categories:

• Server errors — PostgreSQL returned an ErrorResponse message with structured fields (SQLSTATE code, severity, detail, hint, etc.).
• Transport errors — Network-level failures (connection refused, timeout, TLS handshake failure, etc.).
• Protocol errors — Wire protocol violations (unexpected message, bad encoding).
• Authentication errors — Failed authentication (wrong password, unsupported method).
• Type conversion errors — Failed conversion between Rust and PostgreSQL types.
• Configuration errors — Invalid connection string or parameters.
• Connection state errors — Connection closed, wrong state for operation.
• Column/row errors — Column not found, index out of bounds, unexpected NULL.
• Timeout — Operation timed out.
• Pool errors — Connection pool exhaustion or management errors.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Server(Box<PgServerError>)

Error returned by the PostgreSQL server (ErrorResponse).

Contains all fields from the ErrorResponse message: severity, SQLSTATE code, message, detail, hint, position, constraint, etc.

Boxed to reduce the overall size of the enum since PgServerError contains many String and Option fields.

Protocol(ProtocolError)

Wire protocol violation.

Transport(TransportError)

Network/transport error.

Auth(String)

Authentication failure.

TypeConversion(Error)

Type conversion error.

Config(String)

Configuration error (invalid connection string, missing required field, etc.).

ConnectionClosed

Connection is closed.

UnexpectedNull

Unexpected NULL value in a column that was expected to be non-null.

Fields

column: String

ColumnNotFound

Column not found in the result set.

Fields

name: String

ColumnIndexOutOfBounds

Column index out of bounds.

Fields

index: usize

count: usize

Timeout

Operation timed out.

Pool(PoolErrorVariant)

Connection pool error.

InvalidState(String)

Invalid connection state for the requested operation.

Unsupported(String)

The operation is not supported.

Cancelled

Operation was cancelled.

Io(Error)

I/O error.

Tls(Error)

TLS error.

Other(String)

Any other error not covered by the above variants.

Implementations

impl PgError

pub fn is_connection_broken(&self) -> bool

Check if the error indicates the connection is broken and cannot be recovered without reconnecting.

pub fn is_retryable(&self) -> bool

Check if this error is potentially retryable without reconnecting.

pub fn code(&self) -> Option<&str>

Returns the SQLSTATE error code if this is a server error.

pub fn context(self, msg: impl Into<String>) -> Self

Add context to an error by wrapping it in a descriptive message.

Trait Implementations

impl Debug for PgError

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

Formats the value using the given formatter.

impl Display for PgError

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

Formats the value using the given formatter.

impl Error for PgError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<Error> for PgError

fn from(e: TypeConversionError) -> Self

Converts to this type from the input type.

impl From<Error> for PgError

fn from(e: Error) -> Self

Converts to this type from the input type.

impl From<Error> for PgError

Available on crate feature tls only.

fn from(e: Error) -> Self

Converts to this type from the input type.

impl From<PgServerError> for PgError

fn from(e: PgServerError) -> Self

Converts to this type from the input type.

impl From<ProtocolError> for PgError

fn from(e: ProtocolError) -> Self

Converts to this type from the input type.

impl From<TransportError> for PgError

fn from(e: TransportError) -> Self

Converts to this type from the input type.