LXXVIII. PostgreSQL functions

Table 1. Postmaster and PHP

A connection to PostgreSQL server can be established with the following value pairs set in the command string: $conn = pg_connect("host=myHost port=myPort tty=myTTY options=myOptions dbname=myDB user=myUser password=myPassword ");

The previous syntax of: $conn = pg_connect ("host", "port", "options", "tty", "dbname") has been deprecated.

Environmental variable affects PostgreSQL server/client behavior. For example, PostgreSQL module will lookup PGHOST environment variable when hostname is omitted in connection string. Supported environment variables are different from version to version. Refer to PostgreSQL Programmer's Manual (libpq - Environment Variables) for details.

From PostgreSQL 7.1.0, text data type has 1GB as its max size. Older PostgreSQL's text data type is limited by block size. (Default 8KB. Max 32KB defined at compile time)

To use the large object (lo) interface, it is required to enclose large object functions within a transaction block. A transaction block starts with a SQL statement begin and if the transaction was valid ends with commit or end. If the transaction fails the transaction should be closed with rollback or abort.

<?php
    $database = pg_connect ("dbname=jacarta");
    pg_exec ($database, "begin");
    $oid = pg_locreate ($database);
    echo ("$oid\n");
    $handle = pg_loopen ($database, $oid, "w");
    echo ("$handle\n");
    pg_lowrite ($handle, "large object data");
    pg_loclose ($handle);
    pg_exec ($database, "commit");
?>

Table of Contents

pg_close -- Close a PostgreSQL connection

pg_cmdtuples -- Returns number of affected records(tuples)

pg_connect -- Open a PostgreSQL connection

pg_dbname -- Get the database name

pg_end_copy -- Sync with PostgreSQL backend

pg_errormessage -- Get the last error message string of a connection

pg_exec -- Execute a query

pg_fetch_array -- Fetch a row as an array

pg_fetch_object -- Fetch a row as an object

pg_fetch_row -- Get a row as an enumerated array

pg_fieldisnull -- Test if a field is NULL

pg_fieldname -- Returns the name of a field

pg_fieldnum -- Returns the field number of the named field

pg_fieldprtlen -- Returns the printed length

pg_fieldsize --  Returns the internal storage size of the named field

pg_fieldtype --  Returns the type name for the corresponding field number

pg_freeresult -- Free result memory

pg_getlastoid -- Returns the last object's oid

pg_host --  Returns the host name associated with the connection

pg_last_notice --  Returns the last notice message from PostgreSQL server

pg_loclose -- Close a large object

pg_locreate -- Create a large object

pg_loexport -- Export a large object to file

pg_loimport -- Import a large object from file

pg_loopen -- Open a large object

pg_loread -- Read a large object

pg_loreadall --  Read a entire large object and send straight to browser

pg_lounlink -- Delete a large object

pg_lowrite -- Write a large object

pg_numfields -- Returns the number of fields

pg_numrows -- Returns the number of rows

pg_options -- Get the options associated with the connection

pg_pconnect -- Open a persistent PostgreSQL connection

pg_port --  Return the port number associated with the connection

pg_put_line -- Send a NULL-terminated string to PostgreSQL backend

pg_result -- Returns values from a result resource

pg_set_client_encoding --  Set the client encoding

pg_client_encoding --  Get the client encoding

pg_trace -- Enable tracing a PostgreSQL connection

pg_tty --  Return the tty name associated with the connection

pg_untrace -- Disable tracing of a PostgreSQL connection

pg_get_result --  Get asynchronous query result

pg_request_cancel --  Cancel request

pg_is_busy --  Get connection is busy or not

pg_send_query --  Send asynchronous query

pg_cancel_query --  Cancel request

pg_connection_busy --  Get connection is busy or not

pg_connection_reset --  Reset connection (reconnect)

pg_connection_status --  Get connection status

pg_copy_from --  No description given yet

pg_copy_to --  Send null-terminated string to backend server

pg_escape_bytea --  Escape binary for bytea type

pg_escape_string --  Escape string for text/char type

pg_lo_close --  Close a large object

pg_lo_seek --  Seeks position of large object

pg_lo_tell --  Returns current position of large object

pg_result_error --  Get error message associated with result

pg_result_status --  Get status of query result