PostgreSQL

Скачать в pdf «PostgreSQL»


The possible objects are:


If userl gives a privilege WITH GRANT OPTION to user2, and user2 gives it to user3 then userl can revoke this privilege in cascade using the CASCADE keyword.


If userl gives a privilege WITH GRANT OPTION to user2, and user2 gives it to user3, then if userl tries to revoke this privilege it fails if he specifies the RESTRICT keyword.

D.77 ROLLBACK


Name


ROLLBACK — Aborts the current transaction ROLLBACK [ WORK | TRANSACTION ]


Inputs


None.


Outputs


ABORT Message returned if successful.


NOTICE: ROLLBACK: no transaction in progress If there is not any transaction currently in progress.


Description


ROLLBACK rolls back the current transaction and causes all the updates made by the transaction to be discarded.


Notes


Use COMMIT to successfully terminate a transaction. ABORT is a synonym for ROLLBACK. Usage


To abort all changes:


ROLLBACK WORK;


Compatibility


SQL92


SQL92 only specifies the two forms ROLLBACK and ROLLBACK WORK. Otherwise full compatibility.

D.78 SELECT


Name


SELECT — Retrieve rows from a table or view.


SELECT [ ALL | DISTINCT [ ON (expression [,…] ) ] ]


expression [ AS name ][,…]


[ INTO [ temporary | temp ] [ TABLE ] newjable ] [FROM table [ alias ] [,…] ]


[ WHERE condition ]


[group by column [,…] ]


[HAVINGcondition [,…] ]


[ { UNION [ ALL ] | INTERSECT | EXCEPT } select ] [ORDER BY column [ASC | DESC | USING operator ] [,…] ] [ FOR UPDATE [ OF class_name [,…] ] ]

Скачать в pdf «PostgreSQL»