预定义常量

下列常量由此扩展定义，且仅在此扩展编译入 PHP 或在运行时动态载入时可用。

The following constants can be passed to ibase_trans() to specify transaction behaviour.

**Firebird/InterBase transaction flags**
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_VERSION` or `IBASE_REC_NO_VERSION`. This isolation level allows access to changes that were committed after the transaction was started. If `IBASE_REC_NO_VERSION` was specified, only the latest version of a row can be read. If `IBASE_REC_VERSION` was 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.

**Firebird/InterBase fetch flags**
Constant	Description
IBASE_FETCH_BLOBS	Also available as `IBASE_TEXT`for 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: Options to ibase_backup()
IBASE_BKP_IGNORE_LIMBO: Options to ibase_backup()
IBASE_BKP_METADATA_ONLY: Options to ibase_backup()
IBASE_BKP_NO_GARBAGE_COLLECT: Options to ibase_backup()
IBASE_BKP_OLD_DESCRIPTIONS: Options to ibase_backup()
IBASE_BKP_NON_TRANSPORTABLE: Options to ibase_backup()
IBASE_BKP_CONVERT: Options to ibase_backup()
IBASE_RES_DEACTIVATE_IDX: Options to ibase_restore()
IBASE_RES_NO_SHADOW: Options to ibase_restore()
IBASE_RES_NO_VALIDITY: Options to ibase_restore()
IBASE_RES_ONE_AT_A_TIME: Options to ibase_restore()
IBASE_RES_REPLACE
IBASE_RES_CREATE: Options to ibase_restore()
IBASE_RES_USE_ALL_SPACE: Options to ibase_restore()
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: Options to ibase_maintain_db()
IBASE_STS_DATA_PAGES
IBASE_STS_DB_LOG
IBASE_STS_HDR_PAGES
IBASE_STS_IDX_PAGES
IBASE_STS_SYS_RELATIONS: Options to ibase_db_info()
IBASE_SVC_SERVER_VERSION: Options to ibase_server_info()
IBASE_SVC_IMPLEMENTATION: Options to ibase_server_info()
IBASE_SVC_GET_ENV: Options to ibase_server_info()
IBASE_SVC_GET_ENV_LOCK
IBASE_SVC_GET_ENV_MSG
IBASE_SVC_USER_DBPATH
IBASE_SVC_SVR_DB_INFO
IBASE_SVC_GET_USERS: Options to ibase_server_info()