Enum QueryError 

#[non_exhaustive]
pub enum QueryError {
    UnsupportedConstraint,
    InvalidColumnType {
        backend: DatabaseBackend,
        message: String,
    },
    SchemaError(String),
    BackendError {
        backend: DatabaseBackend,
        message: String,
    },
    UnsupportedAction(String),
    Other(String),
}

Errors returned by SQL query generation.

QueryError is #[non_exhaustive], so match arms must include a wildcard.

Matching variants:

use vespertide_query::{QueryError, DatabaseBackend};

fn report(err: &QueryError) -> String {
    match err {
        QueryError::SchemaError(msg) => format!("schema: {msg}"),
        QueryError::InvalidColumnType { backend, message } => {
            format!("type error for {backend:?}: {message}")
        }
        _ => format!("other: {err}"),
    }
}

let schema_err = QueryError::SchemaError("missing table user".into());
assert_eq!(report(&schema_err), "schema: missing table user");

let type_err = QueryError::InvalidColumnType {
    backend: DatabaseBackend::Postgres,
    message: "inet not supported".into(),
};
assert!(report(&type_err).contains("Postgres"));

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.

UnsupportedConstraint

The SQL backend doesn’t support the requested table constraint variant.

InvalidColumnType

A column’s type cannot be mapped to the target SQL backend.

Constructor with named fields:

use vespertide_query::{QueryError, DatabaseBackend};

let err = QueryError::InvalidColumnType {
    backend: DatabaseBackend::MySql,
    message: "inet is not supported by MySQL".into(),
};
assert!(err.to_string().contains("MySql"));
assert!(err.to_string().contains("inet is not supported by MySQL"));

Fields

backend: DatabaseBackend

message: String

SchemaError(String)

A schema validation issue surfaced during query generation (e.g., missing referenced table, malformed constraint).

Constructor and Display:

use vespertide_query::QueryError;

let err = QueryError::SchemaError("referenced table 'user' not found".into());
assert_eq!(err.to_string(), "schema error: referenced table 'user' not found");

BackendError

Backend-specific SQL generation failed.

Fields

backend: DatabaseBackend

message: String

UnsupportedAction(String)

The requested MigrationAction variant isn’t yet supported by query generation.

Other(String)

👎Deprecated since 0.2.0:

Match a specific variant (InvalidColumnType, SchemaError, BackendError, UnsupportedAction)

Fallback variant for errors that don’t fit a specific category yet. Will be removed in a future major version — prefer specific variants when possible.

Trait Implementations

impl Clone for QueryError

fn clone(&self) -> QueryError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for QueryError

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

Formats the value using the given formatter.

impl Display for QueryError

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

Formats the value using the given formatter.

impl Error for QueryError

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.