psycopg2.errors - Exception classes mapping PostgreSQL errors

New in version 2.8.

This module exposes the classes psycopg raises upon receiving an error from the database with a SQLSTATE value attached (available in the pgcode attribute). The content of the module is generated from the PostgreSQL source code and includes classes for every error defined by PostgreSQL in versions between 9.1 and 11.

Every class in the module is named after what referred as "condition name" in the documentation , converted to CamelCase: e.g. the error 22012, division_by_zero is exposed by this module as the class DivisionByZero .

Every exception class is a subclass of one of the standard DB-API exception and expose the Error interface. Each class’ superclass is what used to be raised by psycopg in versions before the introduction of this module, so everything should be compatible with previously written code catching one the DB-API class: if your code used to catch IntegrityError to detect a duplicate entry, it will keep on working even if a more specialised subclass such as UniqueViolation is raised.

The new classes allow a more idiomatic way to check and process a specific error among the many the database may return. For instance, in order to check that a table is locked, the following code could have been used previously:

try:
    cur.execute("LOCK TABLE mytable IN ACCESS EXCLUSIVE MODE NOWAIT")
except psycopg2.OperationalError as e:
    if e.pgcode == psycopg2.errorcodes.LOCK_NOT_AVAILABLE:
        locked = True
    else:
        raise

While this method is still available, the specialised class allows for a more idiomatic error handler:

try:
    cur.execute("LOCK TABLE mytable IN ACCESS EXCLUSIVE MODE NOWAIT")
except psycopg2.errors.LockNotAvailable:
    locked = True
psycopg2.errors. lookup ( code )

Lookup an error code and return its exception class.

Raise KeyError if the code is not found.

try:
    cur.execute("LOCK TABLE mytable IN ACCESS EXCLUSIVE MODE NOWAIT")
except psycopg2.errors.lookup("55P03"):
    locked = True

SQLSTATE exception classes

The following table contains the list of all the SQLSTATE classes exposed by the module.

Note that, for completeness, the module also exposes all the DB-API-defined exceptions and a few psycopg-specific ones exposed by the extensions module, which are not listed here.

SQLSTATE Exception Base exception
Class 02 : No Data (this is also a warning class per the SQL standard)
02000 NoData DatabaseError
02001 NoAdditionalDynamicResultSetsReturned DatabaseError
Class 03 : SQL Statement Not Yet Complete
03000 SqlStatementNotYetComplete DatabaseError
Class 08 : Connection Exception
08000 ConnectionException DatabaseError
08001 SqlclientUnableToEstablishSqlconnection DatabaseError
08003 ConnectionDoesNotExist DatabaseError
08004 SqlserverRejectedEstablishmentOfSqlconnection DatabaseError
08006 ConnectionFailure DatabaseError
08007 TransactionResolutionUnknown DatabaseError
08P01 ProtocolViolation DatabaseError
Class 09 : Triggered Action Exception
09000 TriggeredActionException DatabaseError
Class 0A : Feature Not Supported
0A000 FeatureNotSupported NotSupportedError
Class 0B : Invalid Transaction Initiation
0B000 InvalidTransactionInitiation DatabaseError
Class 0F : Locator Exception
0F000 LocatorException DatabaseError
0F001 InvalidLocatorSpecification DatabaseError
Class 0L : Invalid Grantor
0L000 InvalidGrantor DatabaseError
0LP01 InvalidGrantOperation DatabaseError
Class 0P : Invalid Role Specification
0P000 InvalidRoleSpecification DatabaseError
Class 0Z : Diagnostics Exception
0Z000 DiagnosticsException DatabaseError
0Z002 StackedDiagnosticsAccessedWithoutActiveHandler DatabaseError
Class 20 : Case Not Found
20000 CaseNotFound ProgrammingError
Class 21 : Cardinality Violation
21000 CardinalityViolation ProgrammingError
Class 22 : Data Exception
22000 DataException DataError
22001 StringDataRightTruncation DataError
22002 NullValueNoIndicatorParameter DataError
22003 NumericValueOutOfRange DataError
22004 NullValueNotAllowed DataError
22005 ErrorInAssignment DataError
22007 InvalidDatetimeFormat DataError
22008 DatetimeFieldOverflow DataError
22009 InvalidTimeZoneDisplacementValue DataError
2200B EscapeCharacterConflict DataError
2200C InvalidUseOfEscapeCharacter DataError
2200D InvalidEscapeOctet DataError
2200F ZeroLengthCharacterString DataError
2200G MostSpecificTypeMismatch DataError
2200H SequenceGeneratorLimitExceeded DataError
2200L NotAnXmlDocument DataError
2200M InvalidXmlDocument DataError
2200N InvalidXmlContent DataError
2200S InvalidXmlComment DataError
2200T InvalidXmlProcessingInstruction DataError
22010 InvalidIndicatorParameterValue DataError
22011 SubstringError DataError
22012 DivisionByZero DataError
22013 InvalidPrecedingOrFollowingSize DataError
22014 InvalidArgumentForNtileFunction DataError
22015 IntervalFieldOverflow DataError
22016 InvalidArgumentForNthValueFunction DataError
22018 InvalidCharacterValueForCast DataError
22019 InvalidEscapeCharacter DataError
2201B InvalidRegularExpression DataError
2201E InvalidArgumentForLogarithm DataError
2201F InvalidArgumentForPowerFunction DataError
2201G InvalidArgumentForWidthBucketFunction DataError
2201W InvalidRowCountInLimitClause DataError
2201X InvalidRowCountInResultOffsetClause DataError
22021 CharacterNotInRepertoire DataError
22022 IndicatorOverflow DataError
22023 InvalidParameterValue DataError
22024 UnterminatedCString DataError
22025 InvalidEscapeSequence DataError
22026 StringDataLengthMismatch DataError
22027 TrimError DataError
2202E ArraySubscriptError DataError
2202G InvalidTablesampleRepeat DataError
2202H InvalidTablesampleArgument DataError
22P01 FloatingPointException DataError
22P02 InvalidTextRepresentation DataError
22P03 InvalidBinaryRepresentation DataError
22P04 BadCopyFileFormat DataError
22P05 UntranslatableCharacter DataError
22P06 NonstandardUseOfEscapeCharacter DataError
Class 23 : Integrity Constraint Violation
23000 IntegrityConstraintViolation IntegrityError
23001 RestrictViolation IntegrityError
23502 NotNullViolation IntegrityError
23503 ForeignKeyViolation IntegrityError
23505 UniqueViolation IntegrityError
23514 CheckViolation IntegrityError
23P01 ExclusionViolation IntegrityError
Class 24 : Invalid Cursor State
24000 InvalidCursorState InternalError
Class 25 : Invalid Transaction State
25000 InvalidTransactionState InternalError
25001 ActiveSqlTransaction InternalError
25002 BranchTransactionAlreadyActive InternalError
25003 InappropriateAccessModeForBranchTransaction InternalError
25004 InappropriateIsolationLevelForBranchTransaction InternalError
25005 NoActiveSqlTransactionForBranchTransaction InternalError
25006 ReadOnlySqlTransaction InternalError
25007 SchemaAndDataStatementMixingNotSupported InternalError
25008 HeldCursorRequiresSameIsolationLevel InternalError
25P01 NoActiveSqlTransaction InternalError
25P02 InFailedSqlTransaction InternalError
25P03 IdleInTransactionSessionTimeout InternalError
Class 26 : Invalid SQL Statement Name
26000 InvalidSqlStatementName OperationalError
Class 27 : Triggered Data Change Violation
27000 TriggeredDataChangeViolation OperationalError
Class 28 : Invalid Authorization Specification
28000 InvalidAuthorizationSpecification OperationalError
28P01 InvalidPassword OperationalError
Class 2B : Dependent Privilege Descriptors Still Exist
2B000 DependentPrivilegeDescriptorsStillExist InternalError
2BP01 DependentObjectsStillExist InternalError
Class 2D : Invalid Transaction Termination
2D000 InvalidTransactionTermination InternalError
Class 2F : SQL Routine Exception
2F000 SqlRoutineException InternalError
2F002 ModifyingSqlDataNotPermitted InternalError
2F003 ProhibitedSqlStatementAttempted InternalError
2F004 ReadingSqlDataNotPermitted InternalError
2F005 FunctionExecutedNoReturnStatement InternalError
Class 34 : Invalid Cursor Name
34000 InvalidCursorName OperationalError
Class 38 : External Routine Exception
38000 ExternalRoutineException InternalError
38001 ContainingSqlNotPermitted InternalError
38002 ModifyingSqlDataNotPermittedExt InternalError
38003 ProhibitedSqlStatementAttemptedExt InternalError
38004 ReadingSqlDataNotPermittedExt InternalError
Class 39 : External Routine Invocation Exception
39000 ExternalRoutineInvocationException InternalError
39001 InvalidSqlstateReturned InternalError
39004 NullValueNotAllowedExt InternalError
39P01 TriggerProtocolViolated InternalError
39P02 SrfProtocolViolated InternalError
39P03 EventTriggerProtocolViolated InternalError
Class 3B : Savepoint Exception
3B000 SavepointException InternalError
3B001 InvalidSavepointSpecification InternalError
Class 3D : Invalid Catalog Name
3D000 InvalidCatalogName ProgrammingError
Class 3F : Invalid Schema Name
3F000 InvalidSchemaName ProgrammingError
Class 40 : Transaction Rollback
40000 TransactionRollback OperationalError
40001 SerializationFailure OperationalError
40002 TransactionIntegrityConstraintViolation OperationalError
40003 StatementCompletionUnknown OperationalError
40P01 DeadlockDetected OperationalError
Class 42 : Syntax Error or Access Rule Violation
42000 SyntaxErrorOrAccessRuleViolation ProgrammingError
42501 InsufficientPrivilege ProgrammingError
42601 SyntaxError ProgrammingError
42602 InvalidName ProgrammingError
42611 InvalidColumnDefinition ProgrammingError
42622 NameTooLong ProgrammingError
42701 DuplicateColumn ProgrammingError
42702 AmbiguousColumn ProgrammingError
42703 UndefinedColumn ProgrammingError
42704 UndefinedObject ProgrammingError
42710 DuplicateObject ProgrammingError
42712 DuplicateAlias ProgrammingError
42723 DuplicateFunction ProgrammingError
42725 AmbiguousFunction ProgrammingError
42803 GroupingError ProgrammingError
42804 DatatypeMismatch ProgrammingError
42809 WrongObjectType ProgrammingError
42830 InvalidForeignKey ProgrammingError
42846 CannotCoerce ProgrammingError
42883 UndefinedFunction ProgrammingError
428C9 GeneratedAlways ProgrammingError
42939 ReservedName ProgrammingError
42P01 UndefinedTable ProgrammingError
42P02 UndefinedParameter ProgrammingError
42P03 DuplicateCursor ProgrammingError
42P04 DuplicateDatabase ProgrammingError
42P05 DuplicatePreparedStatement ProgrammingError
42P06 DuplicateSchema ProgrammingError
42P07 DuplicateTable ProgrammingError
42P08 AmbiguousParameter ProgrammingError
42P09 AmbiguousAlias ProgrammingError
42P10 InvalidColumnReference ProgrammingError
42P11 InvalidCursorDefinition ProgrammingError
42P12 InvalidDatabaseDefinition ProgrammingError
42P13 InvalidFunctionDefinition ProgrammingError
42P14 InvalidPreparedStatementDefinition ProgrammingError
42P15 InvalidSchemaDefinition ProgrammingError
42P16 InvalidTableDefinition ProgrammingError
42P17 InvalidObjectDefinition ProgrammingError
42P18 IndeterminateDatatype ProgrammingError
42P19 InvalidRecursion ProgrammingError
42P20 WindowingError ProgrammingError
42P21 CollationMismatch ProgrammingError
42P22 IndeterminateCollation ProgrammingError
Class 44 : WITH CHECK OPTION Violation
44000 WithCheckOptionViolation ProgrammingError
Class 53 : Insufficient Resources
53000 InsufficientResources OperationalError
53100 DiskFull OperationalError
53200 OutOfMemory OperationalError
53300 TooManyConnections OperationalError
53400 ConfigurationLimitExceeded OperationalError
Class 54 : Program Limit Exceeded
54000 ProgramLimitExceeded OperationalError
54001 StatementTooComplex OperationalError
54011 TooManyColumns OperationalError
54023 TooManyArguments OperationalError
Class 55 : Object Not In Prerequisite State
55000 ObjectNotInPrerequisiteState OperationalError
55006 ObjectInUse OperationalError
55P02 CantChangeRuntimeParam OperationalError
55P03 LockNotAvailable OperationalError
Class 57 : Operator Intervention
57000 OperatorIntervention OperationalError
57014 QueryCanceled OperationalError
57P01 AdminShutdown OperationalError
57P02 CrashShutdown OperationalError
57P03 CannotConnectNow OperationalError
57P04 DatabaseDropped OperationalError
Class 58 : System Error (errors external to PostgreSQL itself)
58000 SystemError OperationalError
58030 IoError OperationalError
58P01 UndefinedFile OperationalError
58P02 DuplicateFile OperationalError
Class 72 : Snapshot Failure
72000 SnapshotTooOld DatabaseError
Class F0 : Configuration File Error
F0000 ConfigFileError InternalError
F0001 LockFileExists InternalError
Class HV : Foreign Data Wrapper Error (SQL/MED)
HV000 FdwError OperationalError
HV001 FdwOutOfMemory OperationalError
HV002 FdwDynamicParameterValueNeeded OperationalError
HV004 FdwInvalidDataType OperationalError
HV005 FdwColumnNameNotFound OperationalError
HV006 FdwInvalidDataTypeDescriptors OperationalError
HV007 FdwInvalidColumnName OperationalError
HV008 FdwInvalidColumnNumber OperationalError
HV009 FdwInvalidUseOfNullPointer OperationalError
HV00A FdwInvalidStringFormat OperationalError
HV00B FdwInvalidHandle OperationalError
HV00C FdwInvalidOptionIndex OperationalError
HV00D FdwInvalidOptionName OperationalError
HV00J FdwOptionNameNotFound OperationalError
HV00K FdwReplyHandle OperationalError
HV00L FdwUnableToCreateExecution OperationalError
HV00M FdwUnableToCreateReply OperationalError
HV00N FdwUnableToEstablishConnection OperationalError
HV00P FdwNoSchemas OperationalError
HV00Q FdwSchemaNotFound OperationalError
HV00R FdwTableNotFound OperationalError
HV010 FdwFunctionSequenceError OperationalError
HV014 FdwTooManyHandles OperationalError
HV021 FdwInconsistentDescriptorInformation OperationalError
HV024 FdwInvalidAttributeValue OperationalError
HV090 FdwInvalidStringLengthOrBufferLength OperationalError
HV091 FdwInvalidDescriptorFieldIdentifier OperationalError
Class P0 : PL/pgSQL Error
P0000 PlpgsqlError InternalError
P0001 RaiseException InternalError
P0002 NoDataFound InternalError
P0003 TooManyRows InternalError
P0004 AssertFailure InternalError
Class XX : Internal Error
XX000 InternalError_ InternalError
XX001 DataCorrupted InternalError
XX002 IndexCorrupted InternalError