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.
The following constants can be passed to ibase_trans() to specify transaction behaviour.
| Constant | Description | 
|---|---|
| IBASE_DEFAULT | The default transaction settings are to be used. This default is determined by the client library, which defines it as IBASE_WRITE|IBASE_CONCURRENCY|IBASE_WAIT in most cases. | 
| IBASE_READ | Starts a read-only transaction. | 
| IBASE_WRITE | Starts a read-write transaction. | 
| IBASE_CONSISTENCY | Starts a transaction with the isolation level set to 'consistency', which means the transaction cannot read from tables that are being modified by other concurrent transactions. | 
| IBASE_CONCURRENCY | Starts a transaction with the isolation level set to 'concurrency' (or 'snapshot'), which means the transaction has access to all tables, but cannot see changes that were committed by other transactions after the transaction was started. | 
| IBASE_COMMITTED | Starts a transaction with the isolation level set to
       'read committed'. This flag should be combined with either IBASE_REC_VERSIONorIBASE_REC_NO_VERSION. This isolation level
       allows access to changes that were committed after the transaction
       was started. IfIBASE_REC_NO_VERSIONwas
       specified, only the latest version of a row can be read. IfIBASE_REC_VERSIONwas specified, a row can
       even be read when a modification to it is pending in a concurrent
       transaction. | 
| IBASE_WAIT | Indicated that a transaction should wait and retry when a conflict occurs. | 
| IBASE_NOWAIT | Indicated that a transaction should fail immediately when a conflict occurs. | 
The following constants can be passed to ibase_fetch_row(), ibase_fetch_assoc() or ibase_fetch_object() to specify fetch behaviour.
| Constant | Description | 
|---|---|
| IBASE_FETCH_BLOBS | Also available as IBASE_TEXTfor backward
       compatibility. Causes BLOB contents to be fetched inline, instead of 
       being fetched as BLOB identifiers. | 
| IBASE_FETCH_ARRAYS | Causes arrays to be fetched inline. Otherwise, array identifiers are returned. Array identifiers can only be used as arguments to INSERT operations, as no functions to handle array identifiers are currently available. | 
| IBASE_UNIXTIME | Causes date and time fields not to be returned as strings, but as UNIX timestamps (the number of seconds since the epoch, which is 1-Jan-1970 0:00 UTC). Might be problematic if used with dates before 1970 on some systems. | 
The following constants are used to pass requests and options to the service API functions (ibase_server_info(), ibase_db_info(), ibase_backup(), ibase_restore() and ibase_maintain_db()). Please refer to the Firebird/InterBase manuals for the meaning of these options.
IBASE_BKP_IGNORE_CHECKSUMS
    IBASE_BKP_IGNORE_LIMBO
    IBASE_BKP_METADATA_ONLY
    IBASE_BKP_NO_GARBAGE_COLLECT
    IBASE_BKP_OLD_DESCRIPTIONS
    IBASE_BKP_NON_TRANSPORTABLE
    IBASE_BKP_CONVERT
    IBASE_RES_DEACTIVATE_IDX
    IBASE_RES_NO_SHADOW
    IBASE_RES_NO_VALIDITY
    IBASE_RES_ONE_AT_A_TIME
    IBASE_RES_REPLACE
    IBASE_RES_CREATE
    IBASE_RES_USE_ALL_SPACE
    IBASE_PRP_PAGE_BUFFERS
    IBASE_PRP_SWEEP_INTERVAL
    IBASE_PRP_SHUTDOWN_DB
    IBASE_PRP_DENY_NEW_TRANSACTIONS
    IBASE_PRP_DENY_NEW_ATTACHMENTS
    IBASE_PRP_RESERVE_SPACE
    IBASE_PRP_RES_USE_FULL
    IBASE_PRP_RES
    IBASE_PRP_WRITE_MODE
    IBASE_PRP_WM_ASYNC
    IBASE_PRP_WM_SYNC
    IBASE_PRP_ACCESS_MODE
    IBASE_PRP_AM_READONLY
    IBASE_PRP_AM_READWRITE
    IBASE_PRP_SET_SQL_DIALECT
    IBASE_PRP_ACTIVATE
    IBASE_PRP_DB_ONLINE
    IBASE_RPR_CHECK_DB
    IBASE_RPR_IGNORE_CHECKSUM
    IBASE_RPR_KILL_SHADOWS
    IBASE_RPR_MEND_DB
    IBASE_RPR_VALIDATE_DB
    IBASE_RPR_FULL
    IBASE_RPR_SWEEP_DB
    IBASE_STS_DATA_PAGES
    IBASE_STS_DB_LOG
    IBASE_STS_HDR_PAGES
    IBASE_STS_IDX_PAGES
    IBASE_STS_SYS_RELATIONS
    IBASE_SVC_SERVER_VERSION
    IBASE_SVC_IMPLEMENTATION
    IBASE_SVC_GET_ENV
    IBASE_SVC_GET_ENV_LOCK
    IBASE_SVC_GET_ENV_MSG
    IBASE_SVC_USER_DBPATH
    IBASE_SVC_SVR_DB_INFO
    IBASE_SVC_GET_USERS