CheckViolation is reported when a check constraint would be violated.

DeadlockDetected is reported when a deadlock is detected.

ExcludeViolation is reported when an exclusion constraint would be violated.

ForeignKeyViolation is reported when a foreign key constraint would be violated.

NotNullViolation is reported when a not null constraint would be violated.

Other is reported when an error does not map to any of the defined codes.

TooManyConnections is reported when the database rejects a connection request due to reaching the maximum number of connections.

TransactionFailed is reported when running a command in a failed transaction, due to some previous command failure.

UniqueViolation is reported when a unique constraint would be violated.

Code describes a specific type of database error.

Severity defines the severity of a database error.