An Embeddable NoSQL Database Engine

UnQLite C/C++ API Reference - Transaction Manager.

Syntax

int unqlite_rollback(unqlite *pDb);

Rollback a write-transaction on the specified database handle.

Description

If a write transaction is open, then all changes made within the transaction are reverted and the current write-transaction is closed (Dropping all exclusive locks on the target database, deletion of the journal file, etc.). Otherwise this routine is a no-op.

Parameters

pDb

A pointer to a unQLite Database Handle.

Return value

UNQLITE_OK is returned on success. Any other return value indicates failure such as:

UNQLITE_READ_ONLY: Read-only database.

UNQLITE_BUSY: Another thread or process have an exclusive lock on the database. In this case, the caller should wait until the lock holder relinquish it.

UNQLITE_IOERR: OS specific error.

UNQLITE_NOMEM: Out of memory (An unlikely scenario).

UNQLITE_ABORT: Another thread have released the database handle.

For a human-readable error message, you can extract the database error log via unqlite_config() with a configuration verb set to UNQLITE_CONFIG_ERR_LOG.