#[non_exhaustive]
pub enum Error {
    InvalidCString(NulError),
    DatabaseError(DatabaseErrorKindBox<dyn DatabaseErrorInformation + Send + Sync>),
    NotFound,
    QueryBuilderError(Box<dyn StdError + Send + Sync>),
    DeserializationError(Box<dyn StdError + Send + Sync>),
    SerializationError(Box<dyn StdError + Send + Sync>),
    RollbackErrorOnCommit {
        rollback_error: Box<Error>,
        commit_error: Box<Error>,
    },
    RollbackTransaction,
    AlreadyInTransaction,
    NotInTransaction,
    BrokenTransactionManager,
}
Expand description

Represents all the ways that a query can fail.

This type is not intended to be exhaustively matched, and new variants may be added in the future without a major version bump.

Variants (Non-exhaustive)

This enum is marked as 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.

InvalidCString(NulError)

The query contained a nul byte.

This should never occur in normal usage.

DatabaseError(DatabaseErrorKindBox<dyn DatabaseErrorInformation + Send + Sync>)

The database returned an error.

While Diesel prevents almost all sources of runtime errors at compile time, it does not attempt to prevent 100% of them. Typically this error will occur from insert or update statements due to a constraint violation.

NotFound

No rows were returned by a query expected to return at least one row.

This variant is only returned by get_result and first. load does not treat 0 rows as an error. If you would like to allow either 0 or 1 rows, call optional on the result.

QueryBuilderError(Box<dyn StdError + Send + Sync>)

The query could not be constructed

An example of when this error could occur is if you are attempting to construct an update statement with no changes (e.g. all fields on the struct are None).

DeserializationError(Box<dyn StdError + Send + Sync>)

An error occurred deserializing the data being sent to the database.

Typically this error means that the stated type of the query is incorrect. An example of when this error might occur in normal usage is attempting to deserialize an infinite date into chrono.

SerializationError(Box<dyn StdError + Send + Sync>)

An error occurred serializing the data being sent to the database.

An example of when this error would be returned is if you attempted to serialize a chrono::NaiveDate earlier than the earliest date supported by PostgreSQL.

RollbackErrorOnCommit

Fields

rollback_error: Box<Error>

The error that was encountered when attempting the rollback

commit_error: Box<Error>

If the rollback attempt resulted from a failed attempt to commit the transaction, you will find the related error here.

An error occurred when attempting rollback of a transaction subsequently to a failed commit attempt.

When a commit attempt fails and Diesel believes that it can attempt a rollback to return the connection back in a usable state (out of that transaction), it attempts it then returns the original error.

If that fails, you get this.

RollbackTransaction

Roll back the current transaction.

You can return this variant inside of a transaction when you want to roll it back, but have no actual error to return. Diesel will never return this variant unless you gave it to us, and it can be safely ignored in error handling.

AlreadyInTransaction

Attempted to perform an operation that cannot be done inside a transaction when a transaction was already open.

NotInTransaction

Attempted to perform an operation that can only be done inside a transaction when no transaction was open

BrokenTransactionManager

Transaction manager broken, likely due to a broken connection. No other operations are possible.

Trait Implementations

Formats the value using the given formatter. Read more

Formats the value using the given formatter. Read more

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

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

👎Deprecated since 1.42.0:

use the Display impl or to_string()

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

Provides type based access to context intended for error reports. Read more

Converts to this type from the input type.

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Convert self to an expression for Diesel’s query builder. Read more

Convert &self to an expression for Diesel’s query builder. Read more

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

Data providers should implement this method to provide all values they are able to provide by using demand. Read more

Converts the given value to a String. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.