# DB++ Functions

Warning

This extension is EXPERIMENTAL. The behaviour of this extension -- including the names of its functions and anything else documented about this extension -- may change without notice in a future release of PHP. Use this extension at your own risk.

## Introduction

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.

## Requirements

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).

## Installation

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.

## Runtime Configuration

This extension has no configuration directives defined in php.ini.

## Resource Types

## 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.

## Predefined Constants

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.

## db++ error codes

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 |

## Table of Contents

- 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