Struct grid_sdk::error::ConstraintViolationError

pub struct ConstraintViolationError { /* fields omitted */ }

An error which is returned because of a database constraint violation.

This error indicates that an update to a database failed because it would have violated a constraint defined as part of the database’s definition. For example, if the database has a table with a unique column, and an attempt to insert an entry which would cause duplication in that column, an error with violation type ConstraintViolationType::Unique will occur.

Although this error maps closely to those generated by relational databases (such as those covered by Diesel), the underlying database does not need to be relational. It could, for example, be a memory or file-backed implementation of a store.

Implementations

impl ConstraintViolationError

pub fn with_violation_type(violation_type: ConstraintViolationType) -> Self

Constructs a new ConstraintViolationError from a specified violation type.

The implementation of std::fmt::Display for this error will use the standard display of the ConstraintViolationType for its message.

Examples

use grid_sdk::error::{ ConstraintViolationError, ConstraintViolationType };

let constraint_violation_error = ConstraintViolationError::with_violation_type(
    ConstraintViolationType::Unique
);
assert_eq!(format!("{}", constraint_violation_error), "Unique constraint violated");

pub fn from_source_with_violation_type(
    violation_type: ConstraintViolationType,
    source: Box<dyn Error>
) -> Self

Constructs a new ConstraintViolationError from a specified source error and violation type.

The implementation of std::fmt::Display for this error will simply pass through the display of the source message unmodified.

Examples

use grid_sdk::error::{ ConstraintViolationError, ConstraintViolationType };

let db_err = std::io::Error::new(std::io::ErrorKind::Other, "db error");
let constraint_violation_error = ConstraintViolationError::from_source_with_violation_type(
    ConstraintViolationType::Unique,
    Box::new(db_err)
);
assert_eq!(format!("{}", constraint_violation_error), "db error");

Trait Implementations

impl Debug for ConstraintViolationError

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

Formats the value using the given formatter.

impl Display for ConstraintViolationError

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

Formats the value using the given formatter.

impl Error for ConstraintViolationError

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

The lower-level source of this error, if any.

fn backtrace(&self) -> Option<&Backtrace>

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

Returns a stack backtrace, if available, of where this error occurred.

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