php-src/ext/pgsql

Please send e-mail to yohgaki@php.net if you have comments for 
pgsql module. I appreciate your feedback.

==== Note For PostgreSQL 7.2 beta ====
Current CVS version (probably 4.0.6 or later) compiles without
modefication.

==== Function Name Change ==== 
Function names are going to be changed to confirm coding
standard. MySQL module has been done this already. Function names will
be changed as follows.

pg_errormessage -> pg_error_message
pg_cmdtuples -> pg_affected_rows
pg_fieldnum -> pg_field_num
and so on. Except pg_cmdtuples, under scores '_'  will be added to 
names. 

Older names will become aliases of new functions for backward
compatibility.

Manual will be updated when this change is commited to CVS source.

==== TODO ===
Add pg_result_error_message() to get error messages associated with 
result resource.
Add pg_lotell(), pg_lolseek().
Add pg_escape(). This function requires PostgreSQL 7.2 or later.
Add pg_copy_to() and pg_copy_from() for easier use of copy command.

==== Experimental Async Functions =====
Async query can improve application performance
*significantly*. Please test and report any failure to
yohgaki@php.net 

There are some cases that async functions blocks process. Even if
process was blocked, functions work as expected. (except it blocks
process) These are cases that process is blocked. Refer to libpq
manual for details. Followings are common cases that async functions
are blocked.

 - If libpq is compile with USE_SSL, some async functions are 
   blocked.
 - If libpq under Win32 is *NOT* compiled with 
   WIN32_NON_BLOCKING_CONNECTIONS, non-blocking connection will block. 

Garbages are cleaned when resource is cleaned up. There is no need to
clean up query result if it is not needed.

Please refer to libpq manual or source for details.
These functions are *NOT* supposed to be documented, yet.
API may be changed.

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bool pg_send_query(resource connection, string query) 

Sends async query to backend. Result may be retrieved with
pg_get_result(). It does not accept multiple query, but it accepts
multiple queries at once. Each result may be retrieved separately by
pg_get_result().

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bool pg_request_cancel(resource connection) 

Cancels currently executing async query already sent to PostgreSQL
server. This function is useful when user request time consuming query
to server. It cannot cancel query executed by pg_exec(), since
pg_exec() is a blocking function.

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resource pg_get_result(resource conn) 

Gets pgsql query result resource. Returned value can be fed to
pg_result()/pg_fetch_*(). pg_get_result() may block if result is not
ready to be retrived. Use pg_is_busy() to check result is ready to be
retrieved or not. If multiple query is sent to backend, it may be
retrieved one by one using pg_get_result(). If there is no result left
in connection, it returns false.

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bool pg_is_busy(resource connection)

Returns connections is executing query or not. 

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int pg_status(resource connection)

Gets connection status. It returns PGSQL_CONNECTION_OK or
PGSQL_CONNECTION_BAD.

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bool pg_reset(resource connection)

Resets communication port to Postgresql server using the same
connection parameter. It's useful for error recovery.

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