+ >http://www.druid.net/rides where I have a link at the
+ bottom to the actual
Python code for the
+ page.
+
+
+
+
Constants
+
+ Some constants are defined in the pg module
+ dictionary. They are intended to be used as a parameters for
+ methods calls. You should refer to the libpq
+ description () for more information about
+ them. These constants are:
+
+
+
+ INV_READ
+ INV_WRITE
+ INV_ARCHIVE
+
+ large objects access modes, used by
+ (pgobject.)locreate and
+ (pglarge.)open.
+
+
+
+
+
+ SEEK_SET
+ SEEK_CUR
+ SEEK_END
+
+ positional flags, used by (pglarge.)seek.
+
+
+
+
+
+ version
+ __version__
+
+ constants that give the current version
+
+
+
+
+
+
+
+
+
+
+
<literal>pg</literal> Module Functions
+
+ pg module defines only a few methods that allow
+ to connect to a database and to define default
+ variables that override the environment variables used by
+
+
+ These default variables
were designed to allow you
+ to handle general connection parameters without heavy code in your
+ programs. You can prompt the user for a value, put it in the
+ default variable, and forget it, without having to modify your
+ environment. The support for default variables can be disabled by
+ setting the
-DNO_DEF_VAR option in the Python
+ Setup file. Methods relative to this are specified by te tag [DV].
+
+
+ All variables are set to None at module
+ initialization, specifying that standard environment variables
+ should be used.
+
+
+
+
+ connect
+ PYGRESQL - Connection Management
+
+
+
+ connect
+ opens a connection to the database server
+
+
+
+
+connect(dbname, host, port, opt, tty, user, passwd)
+
+
+
+
Parameters
+
+
+
+ dbname
+
+
+
Name of connected database (string/None).+
+
+
+
+ host
+
+
+
Name of the server host (string/None).+
+
+
+
+ port
+
+
+
Port used by the database server (integer/-1).+
+
+
+
+ opt
+
+
+ Options for the server (string/None).
+
+
+
+
+
+ tty
+
+
+ File or tty for optional debug output from backend
+ (string/None).
+
+
+
+
+
+ user
+
+
+
PostgreSQL user (string/None).
+
+
+
+
+
+ passwd
+
+
+
Password for user (string/None).+
+
+
+
+
+
+
Return Type
+
+
+
+ pgobject
+
+
+ If successful, an object handling a database connection is returned.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad argument type, or too many arguments.
+
+
+
+
+
+ SyntaxError
+
+
+ Duplicate argument definition.
+
+
+
+
+
+ pg.error
+
+
+ Some error occurred during pg connection definition.
+
+
+
+
+
+ (+ all exceptions relative to object allocation)
+
+
+
+
+
+
Description
+
+ This method opens a connection to a specified database on a given
+
PostgreSQL server. You can use
+ keywords here, as described in the
+
Python tutorial. The names of the
+ keywords are the name of the parameters given in the syntax
+ line. For a precise description of the parameters, please refer
+ to the
PostgreSQL user manual.
+
+
+
+
+
Examples
+
+import pg
+
+con1 = pg.connect('testdb', 'myhost', 5432, None, None, 'bob', None)
+con2 = pg.connect(dbname='testdb', host='localhost', user='bob')
+
+
+
+
+
+
+
+
+
+ get_defhost
+ PYGRESQL - Connection Management
+
+
+
+ get_defhost
+ get default host name [DV]
+
+
+
+
+get_defhost()
+
+
+
+
Parameters
+
+ none
+
+
+
+
+
Return Type
+
+
+
+ string or None
+
+
+ Default host specification
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ SyntaxError
+
+
+ Too many arguments.
+
+
+
+
+
+
+
+
+
+
Description
+
+ get_defhost() returns the current default
+ host specification, or None if the environment variables should
+ be used. Environment variables will not be looked up.
+
+
+
+
+
+
+
+
+ set_defhost
+ PYGRESQL - Connection Management
+
+
+ set_defhost
+ set default host name [DV]
+
+
+
+
+set_defhost(host)
+
+
+
+
Parameters
+
+
+
+ host
+
+
+
New default host (string/None).+
+
+
+
+
+
+
Return Type
+
+
+
+ string or None
+
+
+ Previous default host specification.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad argument type, or too many arguments.
+
+
+
+
+
+
+
+
+
+
Description
+ set_defhost() sets the default host value
+ for new connections. If None is supplied as parameter, environment
+ variables will be used in future connections. It returns the
+ previous setting for default host.
+
+
+
+
+
+
+
+
+
+ get_defport
+ PYGRESQL - Connection Management
+
+
+ get_defport
+ get default port [DV]
+
+
+
+
+get_defport()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+
+
+
+ integer or None
+
+
+ Default port specification
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ SyntaxError
+
+
+ Too many arguments.
+
+
+
+
+
+
+
+
+
+
Description
+ get_defport() returns the current default
+ port specification, or None if the environment variables should
+ be used. Environment variables will not be looked up.
+
+
+
+
+
+
+
+
+
+ set_defport
+ PYGRESQL - Connection Management
+
+
+ set_defport
+ set default port [DV]
+
+
+
+
+set_defport(port)
+
+
+
+
Parameters
+
+
+
+ port
+
+
+
New default host (integer/-1).+
+
+
+
+
+
+
Return Type
+
+
+
+ integer or None
+
+
+ Previous default port specification.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad argument type, or too many arguments.
+
+
+
+
+
+
+
+
+
+
Description
+ set_defport() sets the default port value
+ for new connections. If -1 is supplied as parameter, environment
+ variables will be used in future connections. It returns the
+ previous setting for default port.
+
+
+
+
+
+
+
+
+
+ get_defopt
+ PYGRESQL - Connection Management
+
+
+ get_defopt
+ get default options specification [DV]
+
+
+
+
+get_defopt()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+
+
+
+ string or None
+
+
+ Default options specification
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ SyntaxError
+
+
+ Too many arguments.
+
+
+
+
+
+
+
+
+
+
Description
+ get_defopt() returns the current default
+ connection options specification, or None if the environment variables should
+ be used. Environment variables will not be looked up.
+
+
+
+
+
+
+
+
+
+ set_defopt
+ PYGRESQL - Connection Management
+
+
+ set_defopt
+ set options specification [DV]
+
+
+
+
+set_defopt(options)
+
+
+
+
Parameters
+
+
+
+ options
+
+
+
New default connection options (string/None).+
+
+
+
+
+
+
Return Type
+
+
+
+ string or None
+
+
+ Previous default opt specification.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad argument type, or too many arguments.
+
+
+
+
+
+
+
+
+
+
Description
+ set_defopt() sets the default connection options value
+ for new connections. If None is supplied as parameter, environment
+ variables will be used in future connections. It returns the
+ previous setting for default options.
+
+
+
+
+
+
+
+
+
+ get_deftty
+ PYGRESQL - Connection Management
+
+
+ get_deftty
+ get default connection debug terminal specification [DV]
+
+
+
+
+get_deftty()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+
+
+
+ string or None
+
+
+ Default debug terminal specification
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ SyntaxError
+
+
+ Too many arguments.
+
+
+
+
+
+
+
+
+
+
Description
+ get_deftty() returns the current default
+ debug terminal specification, or None if the environment variables should
+ be used. Environment variables will not be looked up.
+
+
+
+
+
+
+
+
+
+ set_deftty
+ PYGRESQL - Connection Management
+
+
+ set_deftty
+ set default debug terminal specification [DV]
+
+
+
+
+set_deftty(terminal)
+
+
+
+
Parameters
+
+
+
+ terminal
+
+
+
New default debug terminal (string/None).+
+
+
+
+
+
+
Return Type
+
+
+
+ string or None
+
+
+ Previous default debug terminal specification.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad argument type, or too many arguments.
+
+
+
+
+
+
+
+
+
+
Description
+ set_deftty() sets the default terminal value
+ for new connections. If None is supplied as parameter, environment
+ variables will be used in future connections. It returns the
+ previous setting for default terminal.
+
+
+
+
+
+
+
+
+
+ get_defbase
+ PYGRESQL - Connection Management
+
+
+ get_defbase
+ get default database name specification [DV]
+
+
+
+
+get_defbase()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+
+
+
+ string or None
+
+
+ Default debug database name specification
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ SyntaxError
+
+
+ Too many arguments.
+
+
+
+
+
+
+
+
+
+
Description
+ get_defbase() returns the current default
+ database name specification, or None if the environment variables should
+ be used. Environment variables will not be looked up.
+
+
+
+
+
+
+
+
+
+ set_defbase
+ PYGRESQL - Connection Management
+
+
+ set_defbase
+ set default database name specification [DV]
+
+
+
+
+set_defbase(database)
+
+
+
+
Parameters
+
+
+
+ database
+
+
+
New default database name (string/None).+
+
+
+
+
+
+
Return Type
+
+
+
+ string or None
+
+
+ Previous default database name specification.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad argument type, or too many arguments.
+
+
+
+
+
+
+
+
+
+
Description
+ set_defbase() sets the default database name
+ for new connections. If None is supplied as parameter, environment
+ variables will be used in future connections. It returns the
+ previous setting for default database name.
+
+
+
+
+
+
+
+
+
+
Connection object: <classname>pgobject</classname>
+
+ This object handles a connection to the
+
PostgreSQL database. It embeds and
+ hides all the parameters that define this connection, leaving just
+ really significant parameters in function calls.
+
+
+ Some methods give direct access to the connection socket. They are
+ specified by the tag [DA]. Do not use them unless you
+ really know what you are doing. If you prefer disabling
+ them, set the -DNO_DIRECT option in the
+
+
+ Some other methods give access to large objects. if you want to
+ forbid access to these from the module, set the
+ -DNO_LARGE option in the
+ These methods are specified by the tag [LO].
+
+
+ Every pgobject defines a set of read-only
+ attributes that describe the connection and its status. These
+ attributes are:
+
+
+
+ host
+
+ the host name of the server (string)
+
+
+
+
+
+ port
+
+ the port of the server (integer)
+
+
+
+
+
+ db
+
+ the selected database (string)
+
+
+
+
+
+ options
+
+ the connection options (string)
+
+
+
+
+
+ tty
+
+ the connection debug terminal (string)
+
+
+
+
+
+ user
+
+ user name on the database system (string)
+
+
+
+
+
+ status
+
+ the status of the connection (integer: 1 - OK, 0 - BAD)
+
+
+
+
+
+ error
+
+ the last warning/error message from the server (string)
+
+
+
+
+
+
+
+
+
+ query
+ PYGRESQL - Query
+
+
+ query
+ executes a SQL command
+
+
+
+
+query(command)
+
+
+
+
Parameters
+
+
+
+ command
+
+
+
+
+
+
+
+
+
Return Type
+
+
+
+ pgqueryobject or None
+
+
+ Result values.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad argument type, or too many arguments.
+
+
+
+
+
+ ValueError
+
+
+ Empty SQL query.
+
+
+
+
+
+ pg.error
+
+
+ Error during query processing, or invalid connection.
+
+
+
+
+
+
+
+
+
+
Description
+
query() method sends a
SQL+ query to the database. If the query is an insert statement, the return
+ value is the
OID of the newly inserted row.
+ If it is otherwise a query that does not return a result
+ (i.e., is not a some kind of SELECT statement), it returns None.
+ Otherwise, it returns a pgqueryobject that can be accessed via the
+ getresult() or dictresult()
+ methods or simply printed.
+
+
+
+
+
+
+
+
+
+ reset
+ PYGRESQL - Reset
+
+
+ reset
+ resets the connection
+
+
+
+
+reset()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+ none
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Too many (any) arguments.
+
+
+
+
+
+
+
+
+
+
Description
+ reset() method resets the current database.
+
+
+
+
+
+
+
+
+
+ close
+ PYGRESQL - Close
+
+
+ close
+ close the database connection
+
+
+
+
+close()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+ none
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Too many (any) arguments.
+
+
+
+
+
+
+
+
+
+
Description
+ close() method closes the database connection.
+ The connection will be closed in any case when the connection is deleted but this
+ allows you to explicitly close it. It is mainly here to allow
+ the DB-SIG API wrapper to implement a close function.
+
+
+
+
+
+
+
+
+
+ fileno
+ PYGRESQL - Fileno
+
+
+ fileno
+ returns the socket used to connect to the database
+
+
+
+
+fileno()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+
+
+
+ socket id
+
+
+ The underlying socket id used to connect to the database.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Too many (any) arguments.
+
+
+
+
+
+
+
+
+
+
Description
+ fileno() method returns the underlying socket id used to connect
+ to the database. This is useful for use in select calls, etc.
+
+
+
+
+
+
+
+
+
+ getnotify
+ PYGRESQL - Getnotify
+
+
+ getnotify
+ gets the last notify from the server
+
+
+
+
+getnotify()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+
+
+
+ tuple, None
+
+
+ Last notify from server
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Too many (any) arguments.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection.
+
+
+
+
+
+
+
+
+
+
Description
+ getnotify() method tries to get a notify from
+ the server (from the SQL statement NOTIFY).
+ If the server returns no notify, the methods returns None.
+ Otherwise, it returns a tuple (couple) (relname, pid),
+ where relname is the name of the notify and pid
+ the process id of the connection that triggered the notify.
+ Remember to do a listen query first otherwise getnotify will always return None.
+
+
+
+
+
+
+
+
+
+ inserttable
+ PYGRESQL - Inserttable
+
+
+ inserttable
+ inserts a list into a table
+
+
+
+
+inserttable(table, values)
+
+
+
+
Parameters
+
+
+
+ table
+
+
+
The table name (string).+
+
+
+
+ values
+
+
+
The list of rows values to insert (list).+
+
+
+
+
+
+
Return Type
+ none
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad argument type or too many (any) arguments.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection.
+
+
+
+
+
+
+
+
+
+
Description
+ inserttable() method allows to quickly
+ insert large blocks of data in a table: it inserts the whole
+ values list into the given table. The list is a list of
+ tuples/lists that define the values for each inserted row. The
+ rows values may contain string, integer, long or double (real)
+ values. Be very careful: this method
+ does not typecheck the fields according to the table
+ definition; it just look whether or not it knows how to handle
+ such types.
+
+
+
+
+
+
+
+
+
+ putline
+ PYGRESQL - Putline
+
+
+ putline
+ writes a line to the server socket [DA]
+
+
+
+
+putline(line)
+
+
+
+
Parameters
+
+
+
+ line
+
+
+
Line to be written (string).+
+
+
+
+
+
+
Return Type
+ none
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad argument type or too many (any) arguments.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection.
+
+
+
+
+
+
+
+
+
+
Description
+ putline() method allows to directly write a string to the server socket.
+
+
+
+
+
+
+
+
+
+ getline
+ PYGRESQL - Getline
+
+
+ getline
+ gets a line from server socket [DA]
+
+
+
+
+getline()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+
+
+
+ string
+
+
+ The line read.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad argument type or too many (any) arguments.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection.
+
+
+
+
+
+
+
+
+
+
Description
+ getline() method allows to directly read a string from the server socket.
+
+
+
+
+
+
+
+
+
+ endcopy
+ PYGRESQL - Endcopy
+
+
+ endcopy
+ synchronizes client and server [DA]
+
+
+
+
+endcopy()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+ none
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad argument type or too many (any) arguments.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection.
+
+
+
+
+
+
+
+
+
+
Description
+ The use of direct access methods may desynchronize client and server. This
+ method ensure that client and server will be synchronized.
+
+
+
+
+
+
+
+
+
+ locreate
+ PYGRESQL - Locreate
+
+
+ locreate
+ creates of large object in the database [LO]
+
+
+
+
+locreate(mode)
+
+
+
+
Parameters
+
+
+
+ mode
+
+
+
Large object create mode.+
+
+
+
+
+
+
Return Type
+
+
+
+ pglarge
+
+
+ Object handling the
PostgreSQL large object.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad argument type or too many arguments.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection, or creation error.
+
+
+
+
+
+
+
+
+
+
Description
+ locreate() method creates a large object in the database.
+ The mode can be defined by OR-ing the constants defined in the pg module
+ (INV_READ, INV_WRITE and INV_ARCHIVE).
+
+
+
+
+
+
+
+
+
+ getlo
+ PYGRESQL - Getlo
+
+
+ getlo
+ builds a large object from given oid [LO]
+
+
+
+
+getlo(oid)
+
+
+
+
Parameters
+
+
+
+ oid
+
+
+
OID of the existing large object (integer).+
+
+
+
+
+
+
Return Type
+
+
+
+ pglarge
+
+
+ Object handling the
PostgreSQL large object.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad argument type or too many arguments.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection.
+
+
+
+
+
+
+
+
+
+
Description
+ getlo() method allows to reuse a formerly
+ created large object through the pglarge interface, providing
+ the user have its oid.
+
+
+
+
+
+
+
+
+
+ loimport
+ PYGRESQL - Loimport
+
+
+ loimport
+
imports a file to a PostgreSQL large object [LO]+
+
+
+
+loimport(filename)
+
+
+
+
Parameters
+
+
+
+ filename
+
+
+
The name of the file to be imported (string).+
+
+
+
+
+
+
Return Type
+
+
+
+ pglarge
+
+
+ Object handling the
PostgreSQL large object.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad argument type or too many arguments.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection, or error during file import.
+
+
+
+
+
+
+
+
+
+
Description
+ loimport() method allows to create large objects
+ in a very simple way. You just give the name of a file containing the
+ data to be use.
+
+
+
+
+
+
+
+
+
+
Database wrapper class: <classname>DB</classname>
+
+ pg module contains a class called
+ DB. All pgobject
+ methods are included in this class also. A number of additional
+ DB class methods are described below. The
+ preferred way to use this module is as follows (See description of
+ the initialization method below.):
+
+import pg
+
+db = pg.DB(...)
+
+for r in db.query(
+ "SELECT foo,bar
+ FROM foo_bar_table
+ WHERE foo !~ bar"
+ ).dictresult():
+
+ print '%(foo)s %(bar)s' % r
+
+
+ The following describes the methods and variables of this class.
+
+
+ The DB class is initialized with the same
+ arguments as the pg.connect method. It also
+ initializes a few internal variables. The statement db =
+ DB() will open the local database with the name of the
+ user just like pg.connect() does.
+
+
+
+
+ pkey
+ PYGRESQL - Pkey
+
+
+ pkey
+ returns the primary key of a table
+
+
+
+
+pkey(table)
+
+
+
+
Parameters
+
+
+
+ table
+
+
+ name of table.
+
+
+
+
+
+
+
+
Return Type
+
+
+
+ string
+
+
+ Name of field which is the primary key of the table.
+
+
+
+
+
+
+
+
+
+
Description
+ pkey() method returns the primary key
+ of a table. Note that this raises an exception if the table
+ does not have a primary key.
+
+
+
+
+
+
+
+
+
+ get_databases
+ PYGRESQL - Get_databases
+
+
+ get_databases
+ get list of databases in the system
+
+
+
+
+get_databases()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+
+
+
+ list
+
+
+ List of databases in the system.
+
+
+
+
+
+
+
+
+
+
Description
+ Although you can do this with a simple select,
+ it is added here for convenience
+
+
+
+
+
+
+
+
+
+ get_tables
+ PYGRESQL - get_tables
+
+
+ get_tables
+ get list of tables in connected database
+
+
+
+
+get_tables()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+
+
+
+ list
+
+
+ List of tables in connected database.
+
+
+
+
+
+
+
+
+
+
Description
+ Although you can do this with a simple select,
+ it is added here for convenience
+
+
+
+
+
+
+
+
+
+ get_attnames
+ PYGRESQL - Get_Attnames
+
+
+ get_attnames
+ returns the attribute names of a table
+
+
+
+
+get_attnames(table)
+
+
+
+
Parameters
+
+
+
+ table
+
+
+ name of table.
+
+
+
+
+
+
+
+
Return Type
+
+
+
+ list
+
+
+ List of attribute names.
+
+
+
+
+
+
+
+
+
+
Description
+ Given the name of a table, digs out the list of attribute names.
+
+
+
+
+
+
+
+
+
+ get
+ PYGRESQL - Get
+
+
+ get
+ get a tuple from a database table
+
+
+
+
+get(table, arg, keyname)
+
+
+
+
Parameters
+
+
+
+ table
+
+
+ Name of table.
+
+
+
+
+
+ arg
+
+
+ Either a dictionary or the value to be looked up.
+
+
+
+
+
+ keyname
+
+
+ Name of field to use as key (optional).
+
+
+
+
+
+
+
+
Return Type
+
+
+
+ dictionary
+
+
+ A dictionary mapping attribute names to row values.
+
+
+
+
+
+
+
+
+
+
Description
+ This method is the basic mechanism to get a single row. It assumes
+ that the key specifies a unique row. If keyname is not specified
+ then the primary key for the table is used. If arg is a dictionary
+ then the value for the key is taken from it and it is modified to
+ include the new values, replacing existing values where necessary.
+ The oid is also put into the dictionary but in order to allow the
+ caller to work with multiple tables, the attribute name is munged
+ to make it unique. It consists of the string oid_ followed by
+ the name of the table.
+
+
+
+
+
+
+
+
+
+ insert
+ PYGRESQL - Insert
+
+
+ insert
+ insert a tuple into a database table
+
+
+
+
+insert(table, a)
+
+
+
+
Parameters
+
+
+
+ table
+
+
+ Name of table.
+
+
+
+
+
+ a
+
+
+ A dictionary of values.
+
+
+
+
+
+
+
+
Return Type
+
+
+
+ integer
+
+
+ The OID of the newly inserted row.
+
+
+
+
+
+
+
+
+
+
Description
+ This method inserts values into the table specified filling in the
+ values from the dictionary. It then reloads the dictionary with the
+ values from the database. This causes the dictionary to be updated
+ with values that are modified by rules, triggers, etc.
+
+
+
+
+
+
+
+
+
+ update
+ PYGRESQL - Update
+
+
+ update
+ update a database table
+
+
+
+
+update(table, a)
+
+
+
+
Parameters
+
+
+
+ table
+
+
+ Name of table.
+
+
+
+
+
+ a
+
+
+ A dictionary of values.
+
+
+
+
+
+
+
+
Return Type
+
+
+
+ integer
+
+
+ The OID of the newly updated row.
+
+
+
+
+
+
+
+
+
+
Description
+ Similar to insert but updates an existing row. The update is based
+ on the OID value as munged by get. The array returned is the
+ one sent modified to reflect any changes caused by the update due
+ to triggers, rules, defaults, etc.
+
+
+
+
+
+
+
+
+
+ clear
+ PYGRESQL - Clear
+
+
+ clear
+ clear a database table
+
+
+
+
+clear(table, a)
+
+
+
+
Parameters
+
+
+
+ table
+
+
+ Name of table.
+
+
+
+
+
+ a
+
+
+ A dictionary of values.
+
+
+
+
+
+
+
+
Return Type
+
+
+
+ dictionary
+
+
+ A dictionary with an empty row.
+
+
+
+
+
+
+
+
+
+
Description
+ This method clears all the attributes to values determined by the types.
+ Numeric types are set to 0, dates are set to 'today' and everything
+ else is set to the empty string. If the array argument is present,
+ it is used as the array and any entries matching attribute names
+ are cleared with everything else left unchanged.
+
+
+
+
+
+
+
+
+
+ delete
+ PYGRESQL - Delete
+
+
+ delete
+ deletes the row from a table
+
+
+
+
+delete(table, a)
+
+
+
+
Parameters
+
+
+
+ table
+
+
+ Name of table.
+
+
+
+
+
+ a
+
+
+ A dictionary of values.
+
+
+
+
+
+
+
+
Return Type
+ none
+
+
+
+
+
+
+
Description
+ This method deletes the row from a table. It deletes based on the OID
+ as munged as described above.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
Query result object: <literal>pgqueryobject</literal>
+
+
+
+
+
+ getresult
+ PYGRESQL - Getresult
+
+
+ getresult
+ gets the values returned by the query
+
+
+
+
+getresult()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+
+
+
+ list
+
+
+ List of tuples.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ SyntaxError
+
+
+ Too many arguments.
+
+
+
+
+
+ pg.error
+
+
+ Invalid previous result.
+
+
+
+
+
+
+
+
+
+
Description
+ getresult() method returns the list of the values returned by the query.
+ More information about this result may be accessed using listfields,
+ fieldname and fieldnum methods.
+
+
+
+
+
+
+
+
+
+ dictresult
+ PYGRESQL - Dictresult
+
+
+ dictresult
+ like getresult but returns a list of dictionaries
+
+
+
+
+dictresult()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+
+
+
+ list
+
+
+ List of dictionaries.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ SyntaxError
+
+
+ Too many arguments.
+
+
+
+
+
+ pg.error
+
+
+ Invalid previous result.
+
+
+
+
+
+
+
+
+
+
Description
+ dictresult() method returns the list of the values returned by the query
+ with each tuple returned as a dictionary with the field names
+ used as the dictionary index.
+
+
+
+
+
+
+
+
+
+ listfields
+ PYGRESQL - Listfields
+
+
+ listfields
+ lists the fields names of the query result
+
+
+
+
+listfields()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+
+
+
+ list
+
+
+ field names
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ SyntaxError
+
+
+ Too many arguments.
+
+
+
+
+
+ pg.error
+
+
+ Invalid query result, or invalid connection.
+
+
+
+
+
+
+
+
+
+
Description
+ listfields() method returns the list of field names defined for the
+ query result. The fields are in the same order as the result values.
+
+
+
+
+
+
+
+
+
+ fieldname
+ PYGRESQL - Fieldname
+
+
+ fieldname
+ field number-name conversion
+
+
+
+
+fieldname(i)
+
+
+
+
Parameters
+
+
+
+ i
+
+
+ field number (integer).
+
+
+
+
+
+
+
+
Return Type
+
+
+
+ string
+
+
+ field name.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad parameter type, or too many arguments.
+
+
+
+
+
+ ValueError
+
+
+ Invalid field number.
+
+
+
+
+
+ pg.error
+
+
+ Invalid query result, or invalid connection.
+
+
+
+
+
+
+
+
+
+
Description
+ fieldname() method allows to find a field name from its rank number. It can be
+ useful for displaying a result. The fields are in the same order than the
+ result values.
+
+
+
+
+
+
+
+
+
+ fieldnum
+ PYGRESQL - Fieldnum
+
+
+ fieldnum
+ field name-number conversion
+
+
+
+
+fieldnum(name)
+
+
+
+
Parameters
+
+
+
+ name
+
+
+ field name (string).
+
+
+
+
+
+
+
+
Return Type
+
+
+
+ integer
+
+
+ field number (integer).
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad parameter type, or too many arguments.
+
+
+
+
+
+ ValueError
+
+
+ Unknown field name.
+
+
+
+
+
+ pg.error
+
+
+ Invalid query result, or invalid connection.
+
+
+
+
+
+
+
+
+
+
Description
+ fieldnum() method returns a field number from its name.
+ It can be used to build a function that converts result list strings to their correct
+ type, using a hardcoded table definition. The number returned is the
+ field rank in the result values list.
+
+
+
+
+
+
+
+
+
+ ntuples
+ PYGRESQL - Ntuples
+
+
+ ntuples
+ returns the number of tuples in query object
+
+
+
+
+ntuples()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+
+
+
+ integer
+
+
+ The number of tuples in query object.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ SyntaxError
+
+
+ Too many arguments.
+
+
+
+
+
+
+
+
+
+
Description
+ ntuples() method returns the number of tuples found in a query.
+
+
+
+
+
+
+
+
+
+
Large Object: <classname>pglarge</classname>
+
+ This object handles all the request concerning a
+
PostgreSQL large object. It embeds and
+ hides all the recurrent
variables (object oid and
+ connection), exactly in the same way
+ pgobjects do, thus only keeping significant
+ parameters in function calls. It keeps a reference to the pgobject
+ used for its creation, sending requests though with its
+ parameters. Any modification but dereferencing the
+ pgobject will thus affect the
+ pglarge object. Dereferencing the initial
+ pgobject is not a problem since
+
Python will not deallocate it before the
+ large object dereference it. All functions return a generic error
+ message on call error, whatever the exact error was. The
+ error attribute of the object allows to
+ get the exact error message.
+
+
+ pglarge objects define a read-only set of
+ attributes that allow to get some information about it. These
+ attributes are:
+
+
+
+ oid
+
+ the oid associated with the object
+
+
+
+
+
+ pgcnx
+
+ the pgobject associated with the object
+
+
+
+
+
+ error
+
+ the last warning/error message of the connection
+
+
+
+
+
+
+
Be careful
+
+ In multithreaded environments, error
+ may be modified by another thread using the same
+ pgobject. Remember these object are
+ shared, not duplicated; you should provide some locking to be
+ able if you want to check this. The oid attribute is very
+ interesting because it allow you reuse the oid later, creating
+ the pglarge object with a pgobject
+ getlo() method call.
+
+
+
+
+ See also for more information about the
+
PostgreSQL large object interface.
+
+
+
+
+
+
+ open
+ PYGRESQL - Open
+
+
+ open
+ opens a large object
+
+
+
+
+open(mode)
+
+
+
+
Parameters
+
+
+
+ mode
+
+
+ open mode definition (integer).
+
+
+
+
+
+
+
+
Return Type
+ none
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad parameter type, or too many arguments.
+
+
+
+
+
+ IOError
+
+
+ Already opened object, or open error.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection.
+
+
+
+
+
+
+
+
+
+
Description
+ open() method opens a large object for reading/writing,
+ in the same way than the
UNIX open()+ function. The mode value can be obtained by OR-ing the constants defined in
+ the pg module (INV_READ, INV_WRITE).
+
+
+
+
+
+
+
+
+
+ close
+ PYGRESQL - Close
+
+
+ close
+ closes the large object
+
+
+
+
+close()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+ none
+
+
+
+
+
Exceptions
+
+
+
+ SyntaxError
+
+
+ Too many arguments.
+
+
+
+
+
+ IOError
+
+
+ Object is not opened, or close error.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection.
+
+
+
+
+
+
+
+
+
+
Description
+ close() method closes previously opened large object,
+ in the same way than the
UNIX close() function.
+
+
+
+
+
+
+
+
+
+ read
+ PYGRESQL - Read
+
+
+ read
+ reads from the large object
+
+
+
+
+read(size)
+
+
+
+
Parameters
+
+
+
+ size
+
+
+ Maximal size of the buffer to be read (integer).
+
+
+
+
+
+
+
+
Return Type
+
+
+
+ string
+
+
+ The read buffer.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad parameter type, or too many arguments.
+
+
+
+
+
+ IOError
+
+
+ Object is not opened, or read error.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection or invalid object.
+
+
+
+
+
+
+
+
+
+
Description
+ read() method allows to read data from the large object,
+ starting at current position.
+
+
+
+
+
+
+
+
+
+ write
+ PYGRESQL - Write
+
+
+ write
+ writes to the large object
+
+
+
+
+write(string)
+
+
+
+
Parameters
+
+
+
+ string
+
+
+ Buffer to be written (string).
+
+
+
+
+
+
+
+
Return Type
+ none
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad parameter type, or too many arguments.
+
+
+
+
+
+ IOError
+
+
+ Object is not opened, or write error.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection or invalid object.
+
+
+
+
+
+
+
+
+
+
Description
+ write() method allows to write data to the large object,
+ starting at current position.
+
+
+
+
+
+
+
+
+
+ seek
+ PYGRESQL - Seek
+
+
+ seek
+ change current position in the large object
+
+
+
+
+seek(offset, whence)
+
+
+
+
Parameters
+
+
+
+ offset
+
+
+ Position offset (integer).
+
+
+
+
+
+ whence
+
+
+ Positional parameter (integer).
+
+
+
+
+
+
+
+
Return Type
+
+
+
+ integer
+
+
+ New current position in the object.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad parameter type, or too many arguments.
+
+
+
+
+
+ IOError
+
+
+ Object is not opened, or seek error.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection or invalid object.
+
+
+
+
+
+
+
+
+
+
Description
+ seek() method allows to move the cursor position
+ in the large object. The whence parameter can be obtained by OR-ing the constants defined in the
+ pg module (SEEK_SET, SEEK_CUR, SEEK_END).
+
+
+
+
+
+
+
+
+
+ tell
+ PYGRESQL - Tell
+
+
+ tell
+ returns current position in the large object
+
+
+
+
+tell()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+
+
+
+ integer
+
+
+ Current position in the object.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ SyntaxError
+
+
+ Too many arguments.
+
+
+
+
+
+ IOError
+
+
+ Object is not opened, or seek error.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection or invalid object.
+
+
+
+
+
+
+
+
+
+
Description
+ tell() method allows to get the current position in the large object.
+
+
+
+
+
+
+
+
+
+ unlink
+ PYGRESQL - Unlink
+
+
+ unlink
+ deletes the large object
+
+
+
+
+unlink()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+ none
+
+
+
+
+
Exceptions
+
+
+
+ SyntaxError
+
+
+ Too many arguments.
+
+
+
+
+
+ IOError
+
+
+ Object is not closed, or unlink error.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection or invalid object.
+
+
+
+
+
+
+
+
+
+
Description
+ unlink() method unlinks (deletes) the large object.
+
+
+
+
+
+
+
+
+
+ size
+ PYGRESQL - Size
+
+
+ size
+ gives the large object size
+
+
+
+
+size()
+
+
+
+
Parameters
+ none
+
+
+
+
+
Return Type
+
+
+
+ integer
+
+
+ The large object size.
+
+
+
+
+
+
+
+
Exceptions
+
+
+
+ SyntaxError
+
+
+ Too many arguments.
+
+
+
+
+
+ IOError
+
+
+ Object is not opened, or seek/tell error.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection or invalid object.
+
+
+
+
+
+
+
+
+
+
Description
+ size() method allows to get the size of
+ the large object. It was implemented because this function
+ is very useful for a WWW interfaced database.
+ Currently the large object needs to be opened.
+
+
+
+
+
+
+
+
+
+ export
+ PYGRESQL - Export
+
+
+ export
+ saves the large object to file
+
+
+
+
+export(filename)
+
+
+
+
Parameters
+
+
+
+ filename
+
+
+ The file to be created.
+
+
+
+
+
+
+
+
Return Type
+ none
+
+
+
+
+
Exceptions
+
+
+
+ TypeError
+
+
+ Bad argument type, or too many arguments.
+
+
+
+
+
+ IOError
+
+
+ Object is not closed, or export error.
+
+
+
+
+
+ pg.error
+
+
+ Invalid connection or invalid object.
+
+
+
+
+
+
+
+
+
+
Description
+ export() method allows to dump the
+ content of a large object in a very simple way.
+ The exported file is created on the host of the program,
+ not the server host.
+
+
+
+
+
+
+
+
+
+
<acronym>DB-API</acronym> Interface
+
+
+ This section needs to be written.
+
+
+ See
+ url="http://www.python.org/topics/database/DatabaseAPI-2.0.html"
+ >http://www.python.org/topics/database/DatabaseAPI-2.0.html
+ for a description of the
DB-API 2.0.
+
+
+
+
projects / postgresql.git / commitdiff