XXIII. DB++ Functions
| Avvertimento |
Questo modulo è SPERIMENTALE. Ovvero, il comportamento di queste funzioni, i nomi di queste funzioni, in definitiva tutto ciò che è documentato qui può cambiare nei futuri rilasci del PHP senza preavviso. Siete avvisati, l'uso di questo modulo è a vostro rischio. |
Introduzione
db++, made by the German company Concept asa, is a relational database system with high performance and low memory and disk usage in mind. While providing SQL as an additional language interface, it is not really a SQL database in the first place but provides its own AQL query language which is much more influenced by the relational algebra than SQL is.
Concept asa always had an interest in supporting open source languages, db++ has had Perl and Tcl call interfaces for years now and uses Tcl as its internal stored procedure language.
Requisiti
This extension relies on external client libraries so you have to have a db++ client installed on the system you want to use this extension on.
Concept asa provides db++ Demo versions and documentation for Linux, some other Unix versions. There is also a Windows version of db++, but this extension doesn't support it (yet).
Installazione
In order to build this extension yourself you need the db++ client libraries and header files to be installed on your system (these are included in the db++ installation archives by default). You have to run configure with option --with-dbplus to build this extension.
configure looks for the client libraries and header files under the default paths /usr/dbplus, /usr/local/dbplus and /opt/dblus. If you have installed db++ in a different place you have add the installation path to the configure option like this: --with-dbplus=/your/installation/path.
Configurazione di Runtime
Questa estensione non definisce alcuna direttiva di configurazione in php.ini
Tipi di risorse
dbplus_relation
Most db++ functions operate on or return dbplus_relation resources. A dbplus_relation is a handle to a stored relation or a relation generated as the result of a query.
Costanti predefinite
Queste costanti sono definite da questa estensione e sono disponibili solo se l'estensione è stata compilata nel PHP o se è stata caricata dinamicamente a runtime.
db++ error codes
Tabella 1. DB++ Error Codes
| 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 |
- Sommario
- dbplus_add -- Add a tuple to a relation
- dbplus_aql -- Perform AQL query
- dbplus_chdir -- Get/Set database virtual current directory
- dbplus_close -- Close a relation
- dbplus_curr -- Get current tuple from relation
- dbplus_errcode -- Get error string for given errorcode or last error
- dbplus_errno -- Get error code for last operation
- dbplus_find -- Set a constraint on a relation
- dbplus_first -- Get first tuple from relation
- dbplus_flush -- Flush all changes made on a relation
- dbplus_freealllocks -- Free all locks held by this client
- dbplus_freelock -- Release write lock on tuple
- dbplus_freerlocks -- Free all tuple locks on given relation
- dbplus_getlock -- Get a write lock on a tuple
- dbplus_getunique -- Get an id number unique to a relation
- dbplus_info -- Get information about a relation
- dbplus_last -- Get last tuple from relation
- dbplus_lockrel -- Request write lock on relation
- dbplus_next -- Get next tuple from relation
- dbplus_open -- Open relation file
- dbplus_prev -- Get previous tuple from relation
- dbplus_rchperm -- Change relation permissions
- dbplus_rcreate -- Creates a new DB++ relation
- dbplus_rcrtexact -- Creates an exact but empty copy of a relation including indices
- dbplus_rcrtlike -- Creates an empty copy of a relation with default indices
- dbplus_resolve -- Resolve host information for relation
- dbplus_restorepos -- Restore position
- dbplus_rkeys -- Specify new primary key for a relation
- dbplus_ropen -- Open relation file local
- dbplus_rquery -- Perform local (raw) AQL query
- dbplus_rrename -- Rename a relation
- dbplus_rsecindex -- Create a new secondary index for a relation
- dbplus_runlink -- Remove relation from filesystem
- dbplus_rzap -- Remove all tuples from relation
- dbplus_savepos -- Save position
- dbplus_setindex -- Set index
- dbplus_setindexbynumber -- Set index by number
- dbplus_sql -- Perform SQL query
- dbplus_tcl -- Execute TCL code on server side
- dbplus_tremove -- Remove tuple and return new current tuple
- dbplus_undo -- Undo
- dbplus_undoprepare -- Prepare undo
- dbplus_unlockrel -- Give up write lock on relation
- dbplus_unselect -- Remove a constraint from relation
- dbplus_update -- Update specified tuple in relation
- dbplus_xlockrel -- Request exclusive lock on relation
- dbplus_xunlockrel -- Free exclusive lock on relation