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SQLite Result Codes
Many of the routines in the SQLite C-language Interface return numeric result codes indicating either success or failure, and in the event of a failure, providing some idea of the cause of the failure. This document strives to explain what each of those numeric result codes means.
Result Codes versus Error Codes
"Error codes" are a subset of "result codes" that indicate that something has gone wrong. There are only a few non-error result codes: SQLITE_OK, SQLITE_ROW, and SQLITE_DONE. The term "error code" means any result code other than these three.
Primary Result Codes versus Extended Result Codes
Result codes are signed 32-bit integers. The least significant 8 bits of the result code define a broad category and are called the "primary result code". More significant bits provide more detailed information about the error and are called the "extended result code"
Note that the primary result code is always a part of the extended result code. Given a full 32-bit extended result code, the application can always find the corresponding primary result code merely by extracting the least significant 8 bits of the extended result code.
All extended result codes are also error codes. Hence the terms "extended result code" and "extended error code" are interchangeable.
For historic compatibility, the C-language interfaces return primary result codes by default. The extended result code for the most recent error can be retrieved using the sqlite3_extended_errcode() interface. The sqlite3_extended_result_codes() interface can be used to put a database connection into a mode where it returns the extended result codes instead of the primary result codes.
Definitions
All result codes are integers. Symbolic names for all result codes are created using "#define" macros in the sqlite3.h header file. There are separate sections in the sqlite3.h header file for the result code definitions and the extended result code definitions.
Primary result code symbolic names are of the form "SQLITE_XXXXXX" where XXXXXX is a sequence of uppercase alphabetic characters. Extended result code names are of the form "SQLITE_XXXXXX_YYYYYYY" where the XXXXXX part is the corresponding primary result code and the YYYYYYY is an extension that further classifies the result code.
The names and numeric values for existing result codes are fixed and unchanging. However, new result codes, and especially new extended result codes, might appear in future releases of SQLite.
Primary Result Code List
The 31 result codes are defined in sqlite3.h and are listed in alphabetical order below:
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Extended Result Code List
The 52 extended result codes are defined in sqlite3.h and are listed in alphabetical order below:
Result Code Meanings
The meanings for all 83 result code values are shown below, in numeric order.
(0) SQLITE_OK
The SQLITE_OK result code means that the operation was successful and that there were no errors. Most other result codes indicate an error.(1) SQLITE_ERROR
The SQLITE_ERROR result code is a generic error code that is used when no other more specific error code is available.(2) SQLITE_INTERNAL
The SQLITE_INTERNAL result code indicates an internal malfunction. In a working version of SQLite, an application should never see this result code. If application does encounter this result code, it shows that there is a bug in the database engine.SQLite does not currently generate this result code. However, application-defined SQL functions or virtual tables, or VFSes, or other extensions might cause this result code to be returned.
(3) SQLITE_PERM
The SQLITE_PERM result code indicates that the requested access mode for a newly created database could not be provided.(4) SQLITE_ABORT
The SQLITE_ABORT result code indicates that an operation was aborted prior to completion, usually be application request. See also: SQLITE_INTERRUPT.If the callback function to sqlite3_exec() returns non-zero, then sqlite3_exec() will return SQLITE_ABORT.
If a ROLLBACK operation occurs on the same database connection as a pending read or write, then the pending read or write may fail with an SQLITE_ABORT or SQLITE_ABORT_ROLLBACK error.
In addition to being a result code, the SQLITE_ABORT value is also used as a conflict resolution mode returned from the sqlite3_vtab_on_conflict() interface.
(5) SQLITE_BUSY
The SQLITE_BUSY result code indicates that the database file could not be written (or in some cases read) because of concurrent activity by some other database connection, usually a database connection in a separate process.For example, if process A is in the middle of a large write transaction and at the same time process B attempts to start a new write transaction, process B will get back an SQLITE_BUSY result because SQLite only supports one writer at a time. Process B will need to wait for process A to finish its transaction before starting a new transaction. The sqlite3_busy_timeout() and sqlite3_busy_handler() interfaces and the busy_timeout pragma are available to process B to help it deal with SQLITE_BUSY errors.
An SQLITE_BUSY error can occur at any point in a transaction: when the transaction is first started, during any write or update operations, or when the transaction commits. To avoid encountering SQLITE_BUSY errors in the middle of a transaction, the application can use BEGIN IMMEDIATE instead of just BEGIN to start a transaction. The BEGIN IMMEDIATE command might itself return SQLITE_BUSY, but if it succeeds, then SQLite guarantees that no subsequent operations on the same database through the next COMMIT will return SQLITE_BUSY.
See also: SQLITE_BUSY_RECOVERY and SQLITE_BUSY_SNAPSHOT.
The SQLITE_BUSY result code differs from SQLITE_LOCKED in that SQLITE_BUSY indicates a conflict with a separate database connection, probably in a separate process, whereas SQLITE_LOCKED indicates a conflict within the same database connection (or sometimes a database connection with a shared cache).
(6) SQLITE_LOCKED
The SQLITE_LOCKED result code indicates that a write operation could not continue because of a conflict within the same database connection or a conflict with a different database connection that uses a shared cache.For example, a DROP TABLE statement cannot be run while another thread is reading from that table on the same database connection because dropping the table would delete the table out from under the concurrent reader.
The SQLITE_LOCKED result code differs from SQLITE_BUSY in that SQLITE_LOCKED indicates a conflict on the same database connection (or on a connection with a shared cache) whereas SQLITE_BUSY indicates a conflict with a different database connection, probably in a different process.
(7) SQLITE_NOMEM
The SQLITE_NOMEM result code indicates that SQLite was unable to allocate all the memory it needed to complete the operation. In other words, an internal call to sqlite3_malloc() or sqlite3_realloc() has failed in a case where the memory being allocated was required in order to continue the operation.(8) SQLITE_READONLY
The SQLITE_READONLY result code is returned when an attempt is made to alter some data for which the current database connection does not have write permission.(9) SQLITE_INTERRUPT
The SQLITE_INTERRUPT result code indicates that an operation was interrupted by the sqlite3_interrupt() interface. See also: SQLITE_ABORT(10) SQLITE_IOERR
The SQLITE_IOERR result code says that the operation could not finish because the operating system reported an I/O error.A full disk drive will normally give an SQLITE_FULL error rather than an SQLITE_IOERR error.
There are many different extended result codes for I/O errors that identify the specific I/O operation that failed.
(11) SQLITE_CORRUPT
The SQLITE_CORRUPT result code indicates that the database file has been corrupted. See the How To Corrupt Your Database Files for further discussion on how corruption can occur.(12) SQLITE_NOTFOUND
The SQLITE_NOTFOUND result code is used in two contexts. SQLITE_NOTFOUND can be returned by the sqlite3_file_control() interface to indicate that the file control opcode passed as the third argument was not recognized by the underlying VFS. SQLITE_NOTFOUND can also be returned by the xSetSystemCall() method of an sqlite3_vfs object.The SQLITE_NOTFOUND result code is also used internally by the SQLite implementation, but those internal uses are not exposed to the application.
(13) SQLITE_FULL
The SQLITE_FULL result code indicates that a write could not complete because the disk is full. Note that this error can occur when trying to write information into the main database file, or it can also occur when writing into temporary disk files.Sometimes applications encounter this error even though there is an abundance of primary disk space because the error occurs when writing into temporary disk files on a system where temporary files are stored on a separate partition with much less space that the primary disk.
(14) SQLITE_CANTOPEN
The SQLITE_CANTOPEN result code indicates that SQLite was unable to open a file. The file in question might be a primary database file or on of several temporary disk files.(15) SQLITE_PROTOCOL
The SQLITE_PROTOCOL result code indicates a problem with the file locking protocol used by SQLite. The SQLITE_PROTOCOL error is currently only returned when using WAL mode and attempting to start a new transaction. There is a race condition that can occur when two separate database connections both try to start a transaction at the same time in WAL mode. The loser of the race backs off and tries again, after a brief delay. If the same connection loses the locking race dozens of times over a span of multiple seconds, it will eventually give up and return SQLITE_PROTOCOL. The SQLITE_PROTOCOL error should appear in practice very, very rarely, and only when there are many separate processes all competing intensely to write to the same database.(16) SQLITE_EMPTY
The SQLITE_EMPTY result code is not currently used.(17) SQLITE_SCHEMA
The SQLITE_SCHEMA result code indicates that the database schema has changed. This result code can be returned from sqlite3_step() for a prepared statement that was generated using sqlite3_prepare() or sqlite3_prepare16(). If the database schema was changed by some other process in between the time that the statement was prepared and the time the statement was run, this error can result.If a prepared statement is generated from sqlite3_prepare_v2() then the statement is automatically re-prepared if the schema changes, up to SQLITE_MAX_SCHEMA_RETRY times (default: 50). The sqlite3_step() interface will only return SQLITE_SCHEMA back to the application if the failure persists after these many retries.
(18) SQLITE_TOOBIG
The SQLITE_TOOBIG error code indicates that a string or BLOB was too large. The default maximum length of a string or BLOB in SQLite is 1,000,000,000 bytes. This maximum length can be changed at compile-time using the SQLITE_MAX_LENGTH compile-time option, or at run-time using the sqlite3_limit(db,SQLITE_LIMIT_LENGTH,...) interface. The SQLITE_TOOBIG error results when SQLite encounters a string or BLOB that exceeds the compile-time or run-time limit.The SQLITE_TOOBIG error code can also result when an oversized SQL statement is passed into one of the sqlite3_prepare_v2() interfaces. The maximum length of an SQL statement defaults to a much smaller value of 1,000,000 bytes. The maximum SQL statement length can be set at compile-time using SQLITE_MAX_SQL_LENGTH or at run-time using sqlite3_limit(db,SQLITE_LIMIT_SQL_LENGTH,...).
(19) SQLITE_CONSTRAINT
The SQLITE_CONSTRAINT error code means that an SQL constraint violation occurred while trying to process an SQL statement. Additional information about the failed constraint can be found by consulting the accompanying error message (returned via sqlite3_errmsg() or sqlite3_errmsg16()) or by looking at the extended error code.(20) SQLITE_MISMATCH
The SQLITE_MISMATCH error code indicates a datatype mismatch.SQLite is normally very forgiving about mismatches between the type of a value and the declared type of the container in which that value is to be stored. For example, SQLite allows the application to store a large BLOB in a column with a declared type of BOOLEAN. But in a few cases, SQLite is strict about types. The SQLITE_MISMATCH error is returned in those few cases when the types do not match.
The rowid of a table must be an integer. Attempt to set the rowid to anything other than an integer (or a NULL which will be automatically converted into the next available integer rowid) results in an SQLITE_MISMATCH error.
(21) SQLITE_MISUSE
The SQLITE_MISUSE return code might be returned if the application uses any SQLite interface in a way that is undefined or unsupported. For example, using a prepared statement after that prepared statement has been finalized might result in an SQLITE_MISUSE error.SQLite tries to detect misuse and report the misuse using this result code. However, there is no guarantee that the detection of misuse will be successful. Misuse detection is probabilistic. Applications should never depend on an SQLITE_MISUSE return value.
If SQLite ever returns SQLITE_MISUSE from any interface, that means that the application is incorrectly coded and needs to be fixed. Do not ship an application that sometimes returns SQLITE_MISUSE from a standard SQLite interface because that application contains potentially serious bugs.
(22) SQLITE_NOLFS
The SQLITE_NOLFS error can be returned on systems that do not support large files when the database grows to be larger than what the filesystem can handle. "NOLFS" stands for "NO Large File Support".(23) SQLITE_AUTH
The SQLITE_AUTH error is returned when the authorizer callback indicates that an SQL statement being prepared is not authorized.(24) SQLITE_FORMAT
The SQLITE_FORMAT error code is not currently used by SQLite.(25) SQLITE_RANGE
The SQLITE_RANGE error indices that the parameter number argument to one of the sqlite3_bind routines or the column number in one of the sqlite3_column routines is out of range.(26) SQLITE_NOTADB
When attempting to open a file, the SQLITE_NOTADB error indicates that the file being opened does not appear to be an SQLite database file.(27) SQLITE_NOTICE
The SQLITE_NOTICE result code is not returned by any C/C++ interface. However, SQLITE_NOTICE (or rather one of its extended error codes) is sometimes used as the first argument in an sqlite3_log() callback to indicate that an unusual operation is taking place.(28) SQLITE_WARNING
The SQLITE_WARNING result code is not returned by any C/C++ interface. However, SQLITE_WARNING (or rather one of its extended error codes) is sometimes used as the first argument in an sqlite3_log() callback to indicate that an unusual and possibly ill-advised operation is taking place.(100) SQLITE_ROW
The SQLITE_ROW result code returned by sqlite3_step() indicates that another row of output is available.(101) SQLITE_DONE
The SQLITE_DONE result code indicates that an operation has completed. The SQLITE_DONE result code is most commonly seen as a return value from sqlite3_step() indicating that the SQL statement has run to completion. But SQLITE_DONE can also be returned by other multi-step interfaces such as sqlite3_backup_step().(261) SQLITE_BUSY_RECOVERY
The SQLITE_BUSY_RECOVERY error code is an extended error code for SQLITE_BUSY that indicates that an operation could not continue because another process is busy recovering a WAL mode database file following a crash. The SQLITE_BUSY_RECOVERY error code only occurs on WAL mode databases.(262) SQLITE_LOCKED_SHAREDCACHE
The SQLITE_LOCKED_SHAREDCACHE error code is an extended error code for SQLITE_LOCKED indicating that the locking conflict has occurred due to contention with a different database connection that happens to hold a shared cache with the database connection to which the error was returned. For example, if the other database connection is holding an exclusive lock on the database, then the database connection that receives this error will be unable to read or write any part of the database file unless it has the read_uncommitted pragma enabled.The SQLITE_LOCKED_SHARECACHE error code works very much like the SQLITE_BUSY error code except that SQLITE_LOCKED_SHARECACHE is for separate database connections that share a cache whereas SQLITE_BUSY is for the much more common case of separate database connections that do not share the same cache. Also, the sqlite3_busy_handler() and sqlite3_busy_timeout() interfaces do not help in resolving SQLITE_LOCKED_SHAREDCACHE conflicts.
(264) SQLITE_READONLY_RECOVERY
The SQLITE_READONLY_RECOVERY error code is an extended error code for SQLITE_READONLY. The SQLITE_READONLY_RECOVERY error code indicates that a WAL mode database cannot be opened because the database file needs to be recovered and recovery requires write access but only read access is available.(266) SQLITE_IOERR_READ
The SQLITE_IOERR_READ error code is an extended error code for SQLITE_IOERR indicating an I/O error in the VFS layer while trying to read from a file on disk. This error might result from a hardware malfunction or because a filesystem came unmounted while the file was open.(267) SQLITE_CORRUPT_VTAB
The SQLITE_CORRUPT_VTAB error code is an extended error code for SQLITE_CORRUPT used by virtual tables. A virtual table might return SQLITE_CORRUPT_VTAB to indicate that content in the virtual table is corrupt.(270) SQLITE_CANTOPEN_NOTEMPDIR
The SQLITE_CANTOPEN_NOTEMPDIR error code is no longer used.(275) SQLITE_CONSTRAINT_CHECK
The SQLITE_CONSTRAINT_CHECK error code is an extended error code for SQLITE_CONSTRAINT indicating that a CHECK constraint failed.(283) SQLITE_NOTICE_RECOVER_WAL
The SQLITE_NOTICE_RECOVER_WAL result code is passed to the callback of sqlite3_log() when a WAL mode database file is recovered.(284) SQLITE_WARNING_AUTOINDEX
The SQLITE_WARNING_AUTOINDEX result code is passed to the callback of sqlite3_log() whenever automatic indexing is used. This can serve as a warning to application designers that the database might benefit from additional indexes.(516) SQLITE_ABORT_ROLLBACK
The SQLITE_ABORT_ROLLBACK error code is an extended error code for SQLITE_ABORT indicating that an SQL statement aborted because the transaction that was active when the SQL statement first started was rolled back. Pending write operations always fail with this error when a rollback occurs. A ROLLBACK will cause a pending read operation to fail only if the schema was changed within the transaction being rolled back.(517) SQLITE_BUSY_SNAPSHOT
The SQLITE_BUSY_SNAPSHOT error code is an extended error code for SQLITE_BUSY that occurs on WAL mode databases when a database connection tries to promote a read transaction into a write transaction but finds that another database connection has already written to the database and thus invalidated prior reads.The following scenario illustrates how an SQLITE_BUSY_SNAPSHOT error might arise:
- Process A starts a read transaction on the database and does one or more SELECT statement. Process A keeps the transaction open.
- Process B updates the database, changing values previous read by process A.
- Process A now tries to write to the database. But process A's view of the database content is now obsolete because process B has modified the database file after process A read from it. Hence process A gets an SQLITE_BUSY_SNAPSHOT error.