The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.
| PHP Constant | db++ constant | meaning | 
|---|---|---|
| DBPLUS_ERR_NOERR (integer) | ERR_NOERR | Null error condition | 
| DBPLUS_ERR_DUPLICATE (integer) | ERR_DUPLICATE | Tried to insert a duplicate tuple | 
| DBPLUS_ERR_EOSCAN (integer) | ERR_EOSCAN | End of scan from rget() | 
| DBPLUS_ERR_EMPTY (integer) | ERR_EMPTY | Relation is empty (server) | 
| DBPLUS_ERR_CLOSE (integer) | ERR_CLOSE | The server can't close | 
| DBPLUS_ERR_WLOCKED (integer) | ERR_WLOCKED | The record is write locked | 
| DBPLUS_ERR_LOCKED (integer) | ERR_LOCKED | Relation was already locked | 
| DBPLUS_ERR_NOLOCK (integer) | ERR_NOLOCK | Relation cannot be locked | 
| DBPLUS_ERR_READ (integer) | ERR_READ | Read error on relation | 
| DBPLUS_ERR_WRITE (integer) | ERR_WRITE | Write error on relation | 
| DBPLUS_ERR_CREATE (integer) | ERR_CREATE | Create() system call failed | 
| DBPLUS_ERR_LSEEK (integer) | ERR_LSEEK | Lseek() system call failed | 
| DBPLUS_ERR_LENGTH (integer) | ERR_LENGTH | Tuple exceeds maximum length | 
| DBPLUS_ERR_OPEN (integer) | ERR_OPEN | Open() system call failed | 
| DBPLUS_ERR_WOPEN (integer) | ERR_WOPEN | Relation already opened for writing | 
| DBPLUS_ERR_MAGIC (integer) | ERR_MAGIC | File is not a relation | 
| DBPLUS_ERR_VERSION (integer) | ERR_VERSION | File is a very old relation | 
| DBPLUS_ERR_PGSIZE (integer) | ERR_PGSIZE | Relation uses a different page size | 
| DBPLUS_ERR_CRC (integer) | ERR_CRC | Invalid crc in the superpage | 
| DBPLUS_ERR_PIPE (integer) | ERR_PIPE | Piped relation requires lseek() | 
| DBPLUS_ERR_NIDX (integer) | ERR_NIDX | Too many secondary indices | 
| DBPLUS_ERR_MALLOC (integer) | ERR_MALLOC | Malloc() call failed | 
| DBPLUS_ERR_NUSERS (integer) | ERR_NUSERS | Error use of max users | 
| DBPLUS_ERR_PREEXIT (integer) | ERR_PREEXIT | Caused by invalid usage | 
| DBPLUS_ERR_ONTRAP (integer) | ERR_ONTRAP | Caused by a signal | 
| DBPLUS_ERR_PREPROC (integer) | ERR_PREPROC | Error in the preprocessor | 
| DBPLUS_ERR_DBPARSE (integer) | ERR_DBPARSE | Error in the parser | 
| DBPLUS_ERR_DBRUNERR (integer) | ERR_DBRUNERR | Run error in db | 
| DBPLUS_ERR_DBPREEXIT (integer) | ERR_DBPREEXIT | Exit condition caused by prexit() * procedure | 
| DBPLUS_ERR_WAIT (integer) | ERR_WAIT | Wait a little (Simple only) | 
| DBPLUS_ERR_CORRUPT_TUPLE (integer) | ERR_CORRUPT_TUPLE | A client sent a corrupt tuple | 
| DBPLUS_ERR_WARNING0 (integer) | ERR_WARNING0 | The Simple routines encountered a non fatal error which was corrected | 
| DBPLUS_ERR_PANIC (integer) | ERR_PANIC | The server should not really die but after a disaster send ERR_PANIC to all its clients | 
| DBPLUS_ERR_FIFO (integer) | ERR_FIFO | Can't create a fifo | 
| DBPLUS_ERR_PERM (integer) | ERR_PERM | Permission denied | 
| DBPLUS_ERR_TCL (integer) | ERR_TCL | TCL_error | 
| DBPLUS_ERR_RESTRICTED (integer) | ERR_RESTRICTED | Only two users | 
| DBPLUS_ERR_USER (integer) | ERR_USER | An error in the use of the library by an application programmer | 
| DBPLUS_ERR_UNKNOWN (integer) | ERR_UNKNOWN |