Add missing python files.
This commit is contained in:
Bruce Momjian
parent
f36e7ff092
commit
439643a668
|
|
@ -0,0 +1,178 @@
|
|||
#! /usr/bin/env python
|
||||
# advanced.py - demo of advanced features of PostGres. Some may not be ANSI.
|
||||
# inspired from the Postgres tutorial
|
||||
# adapted to Python 1995 by Pascal Andre
|
||||
|
||||
print """
|
||||
__________________________________________________________________
|
||||
MODULE ADVANCED.PY : ADVANCED POSTGRES SQL COMMANDS TUTORIAL
|
||||
|
||||
This module is designed for being imported from python prompt
|
||||
|
||||
In order to run the samples included here, first create a connection
|
||||
using : cnx = advanced.DB(...)
|
||||
|
||||
The "..." should be replaced with whatever arguments you need to open an
|
||||
existing database. Usually all you need is the name of the database and,
|
||||
in fact, if it is the same as your login name, you can leave it empty.
|
||||
|
||||
then start the demo with: advanced.demo(cnx)
|
||||
__________________________________________________________________
|
||||
"""
|
||||
|
||||
from pg import DB
|
||||
import sys
|
||||
|
||||
# waits for a key
|
||||
def wait_key():
|
||||
print "Press <enter>"
|
||||
sys.stdin.read(1)
|
||||
|
||||
# inheritance features
|
||||
def inherit_demo(pgcnx):
|
||||
print "-----------------------------"
|
||||
print "-- Inheritance:"
|
||||
print "-- a table can inherit from zero or more tables. A query"
|
||||
print "-- can reference either all rows of a table or all rows "
|
||||
print "-- of a table plus all of its descendants."
|
||||
print "-----------------------------"
|
||||
print
|
||||
print "-- For example, the capitals table inherits from cities table."
|
||||
print "-- (It inherits all data fields from cities.)"
|
||||
print
|
||||
print "CREATE TABLE cities ("
|
||||
print " name text,"
|
||||
print " population float8,"
|
||||
print " altitude int"
|
||||
print ")"
|
||||
print
|
||||
print "CREATE TABLE capitals ("
|
||||
print " state varchar(2)"
|
||||
print ") INHERITS (cities)"
|
||||
pgcnx.query("""CREATE TABLE cities (
|
||||
name text,
|
||||
population float8,
|
||||
altitude int)""")
|
||||
pgcnx.query("""CREATE TABLE capitals (
|
||||
state varchar(2)) INHERITS (cities)""")
|
||||
wait_key()
|
||||
print
|
||||
print "-- now, let's populate the tables"
|
||||
print
|
||||
print "INSERT INTO cities VALUES ('San Francisco', 7.24E+5, 63)"
|
||||
print "INSERT INTO cities VALUES ('Las Vegas', 2.583E+5, 2174)"
|
||||
print "INSERT INTO cities VALUES ('Mariposa', 1200, 1953)"
|
||||
print
|
||||
print "INSERT INTO capitals VALUES ('Sacramento', 3.694E+5, 30, 'CA')"
|
||||
print "INSERT INTO capitals VALUES ('Madison', 1.913E+5, 845, 'WI')"
|
||||
print
|
||||
pgcnx.query("INSERT INTO cities VALUES ('San Francisco', 7.24E+5, 63)")
|
||||
pgcnx.query("INSERT INTO cities VALUES ('Las Vegas', 2.583E+5, 2174)")
|
||||
pgcnx.query("INSERT INTO cities VALUES ('Mariposa', 1200, 1953)")
|
||||
pgcnx.query("INSERT INTO capitals VALUES ('Sacramento',3.694E+5,30,'CA')")
|
||||
pgcnx.query("INSERT INTO capitals VALUES ('Madison', 1.913E+5, 845, 'WI')")
|
||||
print
|
||||
print "SELECT * FROM cities"
|
||||
print pgcnx.query("SELECT * FROM cities")
|
||||
print "SELECT * FROM capitals"
|
||||
print pgcnx.query("SELECT * FROM capitals")
|
||||
print
|
||||
print "-- like before, a regular query references rows of the base"
|
||||
print "-- table only"
|
||||
print
|
||||
print "SELECT name, altitude"
|
||||
print "FROM cities"
|
||||
print "WHERE altitude > 500;"
|
||||
print pgcnx.query("""SELECT name, altitude
|
||||
FROM cities
|
||||
WHERE altitude > 500""")
|
||||
print
|
||||
print "-- on the other hand, you can find all cities, including "
|
||||
print "-- capitals, that are located at an altitude of 500 'ft "
|
||||
print "-- or higher by:"
|
||||
print
|
||||
print "SELECT c.name, c.altitude"
|
||||
print "FROM cities* c"
|
||||
print "WHERE c.altitude > 500"
|
||||
print pgcnx.query("""SELECT c.name, c.altitude
|
||||
FROM cities* c
|
||||
WHERE c.altitude > 500""")
|
||||
|
||||
# arrays attributes
|
||||
def array_demo(pgcnx):
|
||||
print "----------------------"
|
||||
print "-- Arrays:"
|
||||
print "-- attributes can be arrays of base types or user-defined "
|
||||
print "-- types"
|
||||
print "----------------------"
|
||||
print
|
||||
print "CREATE TABLE sal_emp ("
|
||||
print " name text,"
|
||||
print " pay_by_quarter int4[],"
|
||||
print " schedule text[][]"
|
||||
print ")"
|
||||
pgcnx.query("""CREATE TABLE sal_emp (
|
||||
name text,
|
||||
pay_by_quarter int4[],
|
||||
schedule text[][])""")
|
||||
wait_key()
|
||||
print
|
||||
print "-- insert instances with array attributes. "
|
||||
print " Note the use of braces"
|
||||
print
|
||||
print "INSERT INTO sal_emp VALUES ("
|
||||
print " 'Bill',"
|
||||
print " '{10000,10000,10000,10000}',"
|
||||
print " '{{\"meeting\", \"lunch\"}, {}}')"
|
||||
print
|
||||
print "INSERT INTO sal_emp VALUES ("
|
||||
print " 'Carol',"
|
||||
print " '{20000,25000,25000,25000}',"
|
||||
print " '{{\"talk\", \"consult\"}, {\"meeting\"}}')"
|
||||
print
|
||||
pgcnx.query("""INSERT INTO sal_emp VALUES (
|
||||
'Bill', '{10000,10000,10000,10000}',
|
||||
'{{\"meeting\", \"lunch\"}, {}}')""")
|
||||
pgcnx.query("""INSERT INTO sal_emp VALUES (
|
||||
'Carol', '{20000,25000,25000,25000}',
|
||||
'{{\"talk\", \"consult\"}, {\"meeting\"}}')""")
|
||||
wait_key()
|
||||
print
|
||||
print "----------------------"
|
||||
print "-- queries on array attributes"
|
||||
print "----------------------"
|
||||
print
|
||||
print "SELECT name FROM sal_emp WHERE"
|
||||
print " sal_emp.pay_by_quarter[1] <> sal_emp.pay_by_quarter[2]"
|
||||
print
|
||||
print pgcnx.query("""SELECT name FROM sal_emp WHERE
|
||||
sal_emp.pay_by_quarter[1] <> sal_emp.pay_by_quarter[2]""")
|
||||
print
|
||||
print "-- retrieve third quarter pay of all employees"
|
||||
print
|
||||
print "SELECT sal_emp.pay_by_quarter[3] FROM sal_emp"
|
||||
print
|
||||
print pgcnx.query("SELECT sal_emp.pay_by_quarter[3] FROM sal_emp")
|
||||
print
|
||||
print "-- select subarrays"
|
||||
print
|
||||
print "SELECT sal_emp.schedule[1:2][1:1] FROM sal_emp WHERE"
|
||||
print " sal_emp.name = 'Bill'"
|
||||
print pgcnx.query("SELECT sal_emp.schedule[1:2][1:1] FROM sal_emp WHERE " \
|
||||
"sal_emp.name = 'Bill'")
|
||||
|
||||
# base cleanup
|
||||
def demo_cleanup(pgcnx):
|
||||
print "-- clean up (you must remove the children first)"
|
||||
print "DROP TABLE sal_emp"
|
||||
print "DROP TABLE capitals"
|
||||
print "DROP TABLE cities;"
|
||||
pgcnx.query("DROP TABLE sal_emp")
|
||||
pgcnx.query("DROP TABLE capitals")
|
||||
pgcnx.query("DROP TABLE cities")
|
||||
|
||||
# main demo function
|
||||
def demo(pgcnx):
|
||||
inherit_demo(pgcnx)
|
||||
array_demo(pgcnx)
|
||||
demo_cleanup(pgcnx)
|
||||
|
|
@ -0,0 +1,296 @@
|
|||
#! /usr/bin/env python
|
||||
# basics.py - basic SQL commands tutorial
|
||||
# inspired from the Postgres95 tutorial
|
||||
# adapted to Python 1995 by Pascal ANDRE
|
||||
|
||||
print """
|
||||
__________________________________________________________________
|
||||
MODULE BASICS.PY : BASIC POSTGRES SQL COMMANDS TUTORIAL
|
||||
|
||||
This module is designed for being imported from python prompt
|
||||
|
||||
In order to run the samples included here, first create a connection
|
||||
using : cnx = advanced.DB(...)
|
||||
|
||||
The "..." should be replaced with whatever arguments you need to open an
|
||||
existing database. Usually all you need is the name of the database and,
|
||||
in fact, if it is the same as your login name, you can leave it empty.
|
||||
|
||||
then start the demo with: basics.demo(cnx)
|
||||
__________________________________________________________________
|
||||
"""
|
||||
|
||||
from pg import DB
|
||||
import sys
|
||||
|
||||
# waits for a key
|
||||
def wait_key():
|
||||
print "Press <enter>"
|
||||
sys.stdin.read(1)
|
||||
|
||||
# table creation commands
|
||||
def create_table(pgcnx):
|
||||
print "-----------------------------"
|
||||
print "-- Creating a table:"
|
||||
print "-- a CREATE TABLE is used to create base tables. POSTGRES"
|
||||
print "-- SQL has its own set of built-in types. (Note that"
|
||||
print "-- keywords are case-insensitive but identifiers are "
|
||||
print "-- case-sensitive.)"
|
||||
print "-----------------------------"
|
||||
print
|
||||
print "Sending query :"
|
||||
print "CREATE TABLE weather ("
|
||||
print " city varchar(80),"
|
||||
print " temp_lo int,"
|
||||
print " temp_hi int,"
|
||||
print " prcp float8,"
|
||||
print " date date"
|
||||
print ")"
|
||||
pgcnx.query("""CREATE TABLE weather (city varchar(80), temp_lo int,
|
||||
temp_hi int, prcp float8, date date)""")
|
||||
print
|
||||
print "Sending query :"
|
||||
print "CREATE TABLE cities ("
|
||||
print " name varchar(80),"
|
||||
print " location point"
|
||||
print ")"
|
||||
pgcnx.query("""CREATE TABLE cities (
|
||||
name varchar(80),
|
||||
location point)""")
|
||||
|
||||
# data insertion commands
|
||||
def insert_data(pgcnx):
|
||||
print "-----------------------------"
|
||||
print "-- Inserting data:"
|
||||
print "-- an INSERT statement is used to insert a new row into"
|
||||
print "-- a table. There are several ways you can specify what"
|
||||
print "-- columns the data should go to."
|
||||
print "-----------------------------"
|
||||
print
|
||||
print "-- 1. the simplest case is when the list of value correspond to"
|
||||
print "-- the order of the columns specified in CREATE TABLE."
|
||||
print
|
||||
print "Sending query :"
|
||||
print "INSERT INTO weather "
|
||||
print " VALUES ('San Francisco', 46, 50, 0.25, '11/27/1994')"
|
||||
pgcnx.query("""INSERT INTO weather
|
||||
VALUES ('San Francisco', 46, 50, 0.25, '11/27/1994')""")
|
||||
print
|
||||
print "Sending query :"
|
||||
print "INSERT INTO cities "
|
||||
print " VALUES ('San Francisco', '(-194.0, 53.0)')"
|
||||
pgcnx.query("""INSERT INTO cities
|
||||
VALUES ('San Francisco', '(-194.0, 53.0)')""")
|
||||
print
|
||||
wait_key()
|
||||
print "-- 2. you can also specify what column the values correspond "
|
||||
print " to. (The columns can be specified in any order. You may "
|
||||
print " also omit any number of columns. eg. unknown precipitation"
|
||||
print " below)"
|
||||
print "Sending query :"
|
||||
print "INSERT INTO weather (city, temp_lo, temp_hi, prcp, date)"
|
||||
print " VALUES ('San Francisco', 43, 57, 0.0, '11/29/1994')"
|
||||
pgcnx.query("INSERT INTO weather (date, city, temp_hi, temp_lo)" \
|
||||
"VALUES ('11/29/1994', 'Hayward', 54, 37)")
|
||||
|
||||
# direct selection commands
|
||||
def select_data1(pgcnx):
|
||||
print "-----------------------------"
|
||||
print "-- Retrieving data:"
|
||||
print "-- a SELECT statement is used for retrieving data. The "
|
||||
print "-- basic syntax is:"
|
||||
print "-- SELECT columns FROM tables WHERE predicates"
|
||||
print "-----------------------------"
|
||||
print
|
||||
print "-- a simple one would be the query:"
|
||||
print "SELECT * FROM weather"
|
||||
print
|
||||
print "The result is :"
|
||||
q = pgcnx.query("SELECT * FROM weather")
|
||||
print q
|
||||
print
|
||||
print "-- you may also specify expressions in the target list (the "
|
||||
print "-- 'AS column' specifies the column name of the result. It is "
|
||||
print "-- optional.)"
|
||||
print "The query :"
|
||||
print " SELECT city, (temp_hi+temp_lo)/2 AS temp_avg, date "
|
||||
print " FROM weather"
|
||||
print "Gives :"
|
||||
print pgcnx.query("""SELECT city, (temp_hi+temp_lo)/2
|
||||
AS temp_avg, date FROM weather""")
|
||||
print
|
||||
print "-- if you want to retrieve rows that satisfy certain condition"
|
||||
print "-- (ie. a restriction), specify the condition in WHERE. The "
|
||||
print "-- following retrieves the weather of San Francisco on rainy "
|
||||
print "-- days."
|
||||
print "SELECT *"
|
||||
print "FROM weather"
|
||||
print "WHERE city = 'San Francisco' "
|
||||
print " and prcp > 0.0"
|
||||
print pgcnx.query("""SELECT * FROM weather WHERE city = 'San Francisco'
|
||||
AND prcp > 0.0""")
|
||||
print
|
||||
print "-- here is a more complicated one. Duplicates are removed when "
|
||||
print "-- DISTINCT is specified. ORDER BY specifies the column to sort"
|
||||
print "-- on. (Just to make sure the following won't confuse you, "
|
||||
print "-- DISTINCT and ORDER BY can be used separately.)"
|
||||
print "SELECT DISTINCT city"
|
||||
print "FROM weather"
|
||||
print "ORDER BY city;"
|
||||
print pgcnx.query("SELECT DISTINCT city FROM weather ORDER BY city")
|
||||
|
||||
# selection to a temporary table
|
||||
def select_data2(pgcnx):
|
||||
print "-----------------------------"
|
||||
print "-- Retrieving data into other classes:"
|
||||
print "-- a SELECT ... INTO statement can be used to retrieve "
|
||||
print "-- data into another class."
|
||||
print "-----------------------------"
|
||||
print
|
||||
print "The query :"
|
||||
print "SELECT * INTO TABLE temptab "
|
||||
print "FROM weather"
|
||||
print "WHERE city = 'San Francisco' "
|
||||
print " and prcp > 0.0"
|
||||
pgcnx.query("""SELECT * INTO TABLE temptab FROM weather
|
||||
WHERE city = 'San Francisco' and prcp > 0.0""")
|
||||
print "Fills the table temptab, that can be listed with :"
|
||||
print "SELECT * from temptab"
|
||||
print pgcnx.query("SELECT * from temptab")
|
||||
|
||||
# aggregate creation commands
|
||||
def create_aggregate(pgcnx):
|
||||
print "-----------------------------"
|
||||
print "-- Aggregates"
|
||||
print "-----------------------------"
|
||||
print
|
||||
print "Let's consider the query :"
|
||||
print "SELECT max(temp_lo)"
|
||||
print "FROM weather;"
|
||||
print pgcnx.query("SELECT max(temp_lo) FROM weather")
|
||||
print
|
||||
print "-- Aggregate with GROUP BY"
|
||||
print "SELECT city, max(temp_lo)"
|
||||
print "FROM weather "
|
||||
print "GROUP BY city;"
|
||||
print pgcnx.query( """SELECT city, max(temp_lo)
|
||||
FROM weather GROUP BY city""")
|
||||
|
||||
# table join commands
|
||||
def join_table(pgcnx):
|
||||
print "-----------------------------"
|
||||
print "-- Joining tables:"
|
||||
print "-- queries can access multiple tables at once or access"
|
||||
print "-- the same table in such a way that multiple instances"
|
||||
print "-- of the table are being processed at the same time."
|
||||
print "-----------------------------"
|
||||
print
|
||||
print "-- suppose we want to find all the records that are in the "
|
||||
print "-- temperature range of other records. W1 and W2 are aliases "
|
||||
print "--for weather."
|
||||
print
|
||||
print "SELECT W1.city, W1.temp_lo, W1.temp_hi, "
|
||||
print " W2.city, W2.temp_lo, W2.temp_hi"
|
||||
print "FROM weather W1, weather W2"
|
||||
print "WHERE W1.temp_lo < W2.temp_lo "
|
||||
print " and W1.temp_hi > W2.temp_hi"
|
||||
print
|
||||
print pgcnx.query("""SELECT W1.city, W1.temp_lo, W1.temp_hi,
|
||||
W2.city, W2.temp_lo, W2.temp_hi FROM weather W1, weather W2
|
||||
WHERE W1.temp_lo < W2.temp_lo and W1.temp_hi > W2.temp_hi""")
|
||||
print
|
||||
print "-- let's join two tables. The following joins the weather table"
|
||||
print "-- and the cities table."
|
||||
print
|
||||
print "SELECT city, location, prcp, date"
|
||||
print "FROM weather, cities"
|
||||
print "WHERE name = city"
|
||||
print
|
||||
print pgcnx.query("""SELECT city, location, prcp, date FROM weather, cities
|
||||
WHERE name = city""")
|
||||
print
|
||||
print "-- since the column names are all different, we don't have to "
|
||||
print "-- specify the table name. If you want to be clear, you can do "
|
||||
print "-- the following. They give identical results, of course."
|
||||
print
|
||||
print "SELECT w.city, c.location, w.prcp, w.date"
|
||||
print "FROM weather w, cities c"
|
||||
print "WHERE c.name = w.city;"
|
||||
print
|
||||
print pgcnx.query("""SELECT w.city, c.location, w.prcp, w.date
|
||||
FROM weather w, cities c WHERE c.name = w.city""")
|
||||
|
||||
# data updating commands
|
||||
def update_data(pgcnx):
|
||||
print "-----------------------------"
|
||||
print "-- Updating data:"
|
||||
print "-- an UPDATE statement is used for updating data. "
|
||||
print "-----------------------------"
|
||||
print
|
||||
print "-- suppose you discover the temperature readings are all off by"
|
||||
print "-- 2 degrees as of Nov 28, you may update the data as follow:"
|
||||
print
|
||||
print "UPDATE weather"
|
||||
print " SET temp_hi = temp_hi - 2, temp_lo = temp_lo - 2"
|
||||
print " WHERE date > '11/28/1994'"
|
||||
print
|
||||
pgcnx.query("""UPDATE weather
|
||||
SET temp_hi = temp_hi - 2, temp_lo = temp_lo - 2
|
||||
WHERE date > '11/28/1994'""")
|
||||
print
|
||||
print "SELECT * from weather"
|
||||
print pgcnx.query("SELECT * from weather")
|
||||
|
||||
# data deletion commands
|
||||
def delete_data(pgcnx):
|
||||
print "-----------------------------"
|
||||
print "-- Deleting data:"
|
||||
print "-- a DELETE statement is used for deleting rows from a "
|
||||
print "-- table."
|
||||
print "-----------------------------"
|
||||
print
|
||||
print "-- suppose you are no longer interested in the weather of "
|
||||
print "-- Hayward, you can do the following to delete those rows from"
|
||||
print "-- the table"
|
||||
print
|
||||
print "DELETE FROM weather WHERE city = 'Hayward'"
|
||||
pgcnx.query("DELETE FROM weather WHERE city = 'Hayward'")
|
||||
print
|
||||
print "SELECT * from weather"
|
||||
print
|
||||
print pgcnx.query("SELECT * from weather")
|
||||
print
|
||||
print "-- you can also delete all the rows in a table by doing the "
|
||||
print "-- following. (This is different from DROP TABLE which removes "
|
||||
print "-- the table in addition to the removing the rows.)"
|
||||
print
|
||||
print "DELETE FROM weather"
|
||||
pgcnx.query("DELETE FROM weather")
|
||||
print
|
||||
print "SELECT * from weather"
|
||||
print pgcnx.query("SELECT * from weather")
|
||||
|
||||
# table removal commands
|
||||
def remove_table(pgcnx):
|
||||
print "-----------------------------"
|
||||
print "-- Removing the tables:"
|
||||
print "-- DROP TABLE is used to remove tables. After you have"
|
||||
print "-- done this, you can no longer use those tables."
|
||||
print "-----------------------------"
|
||||
print
|
||||
print "DROP TABLE weather, cities, temptab"
|
||||
pgcnx.query("DROP TABLE weather, cities, temptab")
|
||||
|
||||
# main demo function
|
||||
def demo(pgcnx):
|
||||
create_table(pgcnx)
|
||||
wait_key()
|
||||
insert_data(pgcnx)
|
||||
wait_key()
|
||||
select_data1(pgcnx)
|
||||
select_data2(pgcnx)
|
||||
create_aggregate(pgcnx)
|
||||
join_table(pgcnx)
|
||||
update_data(pgcnx)
|
||||
delete_data(pgcnx)
|
||||
remove_table(pgcnx)
|
||||
|
|
@ -0,0 +1,205 @@
|
|||
# func.py - demonstrate the use of SQL functions
|
||||
# inspired from the PostgreSQL tutorial
|
||||
# adapted to Python 1995 by Pascal ANDRE
|
||||
|
||||
print """
|
||||
__________________________________________________________________
|
||||
MODULE FUNC.PY : SQL FUNCTION DEFINITION TUTORIAL
|
||||
|
||||
This module is designed for being imported from python prompt
|
||||
|
||||
In order to run the samples included here, first create a connection
|
||||
using : cnx = advanced.DB(...)
|
||||
|
||||
The "..." should be replaced with whatever arguments you need to open an
|
||||
existing database. Usually all you need is the name of the database and,
|
||||
in fact, if it is the same as your login name, you can leave it empty.
|
||||
|
||||
then start the demo with: func.demo(cnx)
|
||||
__________________________________________________________________
|
||||
"""
|
||||
|
||||
from pg import DB
|
||||
import sys
|
||||
|
||||
# waits for a key
|
||||
def wait_key():
|
||||
print "Press <enter>"
|
||||
sys.stdin.read(1)
|
||||
|
||||
# basic functions declaration
|
||||
def base_func(pgcnx):
|
||||
print "-----------------------------"
|
||||
print "-- Creating SQL Functions on Base Types"
|
||||
print "-- a CREATE FUNCTION statement lets you create a new "
|
||||
print "-- function that can be used in expressions (in SELECT, "
|
||||
print "-- INSERT, etc.). We will start with functions that "
|
||||
print "-- return values of base types."
|
||||
print "-----------------------------"
|
||||
print
|
||||
print "--"
|
||||
print "-- let's create a simple SQL function that takes no arguments"
|
||||
print "-- and returns 1"
|
||||
print
|
||||
print "CREATE FUNCTION one() RETURNS int4"
|
||||
print " AS 'SELECT 1 as ONE' LANGUAGE 'sql'"
|
||||
pgcnx.query("""CREATE FUNCTION one() RETURNS int4
|
||||
AS 'SELECT 1 as ONE' LANGUAGE 'sql'""")
|
||||
wait_key()
|
||||
print
|
||||
print "--"
|
||||
print "-- functions can be used in any expressions (eg. in the target"
|
||||
print "-- list or qualifications)"
|
||||
print
|
||||
print "SELECT one() AS answer"
|
||||
print pgcnx.query("SELECT one() AS answer")
|
||||
print
|
||||
print "--"
|
||||
print "-- here's how you create a function that takes arguments. The"
|
||||
print "-- following function returns the sum of its two arguments:"
|
||||
print
|
||||
print "CREATE FUNCTION add_em(int4, int4) RETURNS int4"
|
||||
print " AS 'SELECT $1 + $2' LANGUAGE 'sql'"
|
||||
pgcnx.query("""CREATE FUNCTION add_em(int4, int4) RETURNS int4
|
||||
AS 'SELECT $1 + $2' LANGUAGE 'sql'""")
|
||||
print
|
||||
print "SELECT add_em(1, 2) AS answer"
|
||||
print pgcnx.query("SELECT add_em(1, 2) AS answer")
|
||||
|
||||
# functions on composite types
|
||||
def comp_func(pgcnx):
|
||||
print "-----------------------------"
|
||||
print "-- Creating SQL Functions on Composite Types"
|
||||
print "-- it is also possible to create functions that return"
|
||||
print "-- values of composite types."
|
||||
print "-----------------------------"
|
||||
print
|
||||
print "-- before we create more sophisticated functions, let's "
|
||||
print "-- populate an EMP table"
|
||||
print
|
||||
print "CREATE TABLE EMP ("
|
||||
print " name text,"
|
||||
print " salary int4,"
|
||||
print " age int4,"
|
||||
print " dept varchar(16)"
|
||||
print ")"
|
||||
pgcnx.query("""CREATE TABLE EMP (
|
||||
name text,
|
||||
salary int4,
|
||||
age int4,
|
||||
dept varchar(16))""")
|
||||
print
|
||||
print "INSERT INTO EMP VALUES ('Sam', 1200, 16, 'toy')"
|
||||
print "INSERT INTO EMP VALUES ('Claire', 5000, 32, 'shoe')"
|
||||
print "INSERT INTO EMP VALUES ('Andy', -1000, 2, 'candy')"
|
||||
print "INSERT INTO EMP VALUES ('Bill', 4200, 36, 'shoe')"
|
||||
print "INSERT INTO EMP VALUES ('Ginger', 4800, 30, 'candy')"
|
||||
pgcnx.query("INSERT INTO EMP VALUES ('Sam', 1200, 16, 'toy')")
|
||||
pgcnx.query("INSERT INTO EMP VALUES ('Claire', 5000, 32, 'shoe')")
|
||||
pgcnx.query("INSERT INTO EMP VALUES ('Andy', -1000, 2, 'candy')")
|
||||
pgcnx.query("INSERT INTO EMP VALUES ('Bill', 4200, 36, 'shoe')")
|
||||
pgcnx.query("INSERT INTO EMP VALUES ('Ginger', 4800, 30, 'candy')")
|
||||
wait_key()
|
||||
print
|
||||
print "-- the argument of a function can also be a tuple. For "
|
||||
print "-- instance, double_salary takes a tuple of the EMP table"
|
||||
print
|
||||
print "CREATE FUNCTION double_salary(EMP) RETURNS int4"
|
||||
print " AS 'SELECT $1.salary * 2 AS salary' LANGUAGE 'sql'"
|
||||
pgcnx.query("""CREATE FUNCTION double_salary(EMP) RETURNS int4
|
||||
AS 'SELECT $1.salary * 2 AS salary' LANGUAGE 'sql'""")
|
||||
print
|
||||
print "SELECT name, double_salary(EMP) AS dream"
|
||||
print "FROM EMP"
|
||||
print "WHERE EMP.dept = 'toy'"
|
||||
print pgcnx.query("""SELECT name, double_salary(EMP) AS dream
|
||||
FROM EMP WHERE EMP.dept = 'toy'""")
|
||||
print
|
||||
print "-- the return value of a function can also be a tuple. However,"
|
||||
print "-- make sure that the expressions in the target list is in the "
|
||||
print "-- same order as the columns of EMP."
|
||||
print
|
||||
print "CREATE FUNCTION new_emp() RETURNS EMP"
|
||||
print " AS 'SELECT \'None\'::text AS name,"
|
||||
print " 1000 AS salary,"
|
||||
print " 25 AS age,"
|
||||
print " \'none\'::varchar(16) AS dept'"
|
||||
print " LANGUAGE 'sql'"
|
||||
pgcnx.query("""CREATE FUNCTION new_emp() RETURNS EMP
|
||||
AS 'SELECT \\\'None\\\'::text AS name,
|
||||
1000 AS salary,
|
||||
25 AS age,
|
||||
\\\'none\\\'::varchar(16) AS dept'
|
||||
LANGUAGE 'sql'""")
|
||||
wait_key()
|
||||
print
|
||||
print "-- you can then project a column out of resulting the tuple by"
|
||||
print "-- using the \"function notation\" for projection columns. "
|
||||
print "-- (ie. bar(foo) is equivalent to foo.bar) Note that we don't"
|
||||
print "-- support new_emp().name at this moment."
|
||||
print
|
||||
print "SELECT name(new_emp()) AS nobody"
|
||||
print pgcnx.query("SELECT name(new_emp()) AS nobody")
|
||||
print
|
||||
print "-- let's try one more function that returns tuples"
|
||||
print "CREATE FUNCTION high_pay() RETURNS setof EMP"
|
||||
print " AS 'SELECT * FROM EMP where salary > 1500'"
|
||||
print " LANGUAGE 'sql'"
|
||||
pgcnx.query("""CREATE FUNCTION high_pay() RETURNS setof EMP
|
||||
AS 'SELECT * FROM EMP where salary > 1500'
|
||||
LANGUAGE 'sql'""")
|
||||
print
|
||||
print "SELECT name(high_pay()) AS overpaid"
|
||||
print pgcnx.query("SELECT name(high_pay()) AS overpaid")
|
||||
|
||||
# function with multiple SQL commands
|
||||
def mult_func(pgcnx):
|
||||
print "-----------------------------"
|
||||
print "-- Creating SQL Functions with multiple SQL statements"
|
||||
print "-- you can also create functions that do more than just a"
|
||||
print "-- SELECT."
|
||||
print "-----------------------------"
|
||||
print
|
||||
print "-- you may have noticed that Andy has a negative salary. We'll"
|
||||
print "-- create a function that removes employees with negative "
|
||||
print "-- salaries."
|
||||
print
|
||||
print "SELECT * FROM EMP"
|
||||
print pgcnx.query("SELECT * FROM EMP")
|
||||
print
|
||||
print "CREATE FUNCTION clean_EMP () RETURNS int4"
|
||||
print " AS 'DELETE FROM EMP WHERE EMP.salary <= 0"
|
||||
print " SELECT 1 AS ignore_this'"
|
||||
print " LANGUAGE 'sql'"
|
||||
pgcnx.query("CREATE FUNCTION clean_EMP () RETURNS int4 AS 'DELETE FROM EMP WHERE EMP.salary <= 0; SELECT 1 AS ignore_this' LANGUAGE 'sql'")
|
||||
print
|
||||
print "SELECT clean_EMP()"
|
||||
print pgcnx.query("SELECT clean_EMP()")
|
||||
print
|
||||
print "SELECT * FROM EMP"
|
||||
print pgcnx.query("SELECT * FROM EMP")
|
||||
|
||||
# base cleanup
|
||||
def demo_cleanup(pgcnx):
|
||||
print "-- remove functions that were created in this file"
|
||||
print
|
||||
print "DROP FUNCTION clean_EMP()"
|
||||
print "DROP FUNCTION high_pay()"
|
||||
print "DROP FUNCTION new_emp()"
|
||||
print "DROP FUNCTION add_em(int4, int4)"
|
||||
print "DROP FUNCTION one()"
|
||||
print
|
||||
print "DROP TABLE EMP"
|
||||
pgcnx.query("DROP FUNCTION clean_EMP()")
|
||||
pgcnx.query("DROP FUNCTION high_pay()")
|
||||
pgcnx.query("DROP FUNCTION new_emp()")
|
||||
pgcnx.query("DROP FUNCTION add_em(int4, int4)")
|
||||
pgcnx.query("DROP FUNCTION one()")
|
||||
pgcnx.query("DROP TABLE EMP")
|
||||
|
||||
# main demo function
|
||||
def demo(pgcnx):
|
||||
base_func(pgcnx)
|
||||
comp_func(pgcnx)
|
||||
mult_func(pgcnx)
|
||||
demo_cleanup(pgcnx)
|
||||
|
|
@ -0,0 +1,147 @@
|
|||
# syscat.py - parses some system catalogs
|
||||
# inspired from the PostgreSQL tutorial
|
||||
# adapted to Python 1995 by Pascal ANDRE
|
||||
|
||||
print """
|
||||
__________________________________________________________________
|
||||
MODULE SYSCAT.PY : PARSES SOME POSTGRESQL SYSTEM CATALOGS
|
||||
|
||||
This module is designed for being imported from python prompt
|
||||
|
||||
In order to run the samples included here, first create a connection
|
||||
using : cnx = advanced.DB(...)
|
||||
|
||||
The "..." should be replaced with whatever arguments you need to open an
|
||||
existing database. Usually all you need is the name of the database and,
|
||||
in fact, if it is the same as your login name, you can leave it empty.
|
||||
|
||||
then start the demo with: syscat.demo(cnx)
|
||||
|
||||
Some results may be empty, depending on your base status."
|
||||
|
||||
__________________________________________________________________
|
||||
"""
|
||||
|
||||
from pg import DB
|
||||
import sys
|
||||
|
||||
# waits for a key
|
||||
def wait_key():
|
||||
print "Press <enter>"
|
||||
sys.stdin.read(1)
|
||||
|
||||
# lists all simple indices
|
||||
def list_simple_ind(pgcnx):
|
||||
result = pgcnx.query("""SELECT bc.relname AS class_name,
|
||||
ic.relname AS index_name, a.attname
|
||||
FROM pg_class bc, pg_class ic, pg_index i, pg_attribute a
|
||||
WHERE i.indrelid = bc.oid AND i.indexrelid = bc.oid
|
||||
AND i.indkey[0] = a.attnum AND a.attrelid = bc.oid
|
||||
AND i.indproc = '0'::oid
|
||||
ORDER BY class_name, index_name, attname""")
|
||||
return result
|
||||
|
||||
# list all user defined attributes and their type in user-defined classes
|
||||
def list_all_attr(pgcnx):
|
||||
result = pgcnx.query("""SELECT c.relname, a.attname, t.typname
|
||||
FROM pg_class c, pg_attribute a, pg_type t
|
||||
WHERE c.relkind = 'r' and c.relname !~ '^pg_'
|
||||
AND c.relname !~ '^Inv' and a.attnum > 0
|
||||
AND a.attrelid = c.oid and a.atttypid = t.oid
|
||||
ORDER BY relname, attname""")
|
||||
return result
|
||||
|
||||
# list all user defined base type
|
||||
def list_user_base_type(pgcnx):
|
||||
result = pgcnx.query("""SELECT u.usename, t.typname
|
||||
FROM pg_type t, pg_user u
|
||||
WHERE u.usesysid = int2in(int4out(t.typowner))
|
||||
AND t.typrelid = '0'::oid and t.typelem = '0'::oid
|
||||
AND u.usename <> 'postgres' order by usename, typname""")
|
||||
return result
|
||||
|
||||
# list all right-unary operators
|
||||
def list_right_unary_operator(pgcnx):
|
||||
result = pgcnx.query("""SELECT o.oprname AS right_unary,
|
||||
lt.typname AS operand, result.typname AS return_type
|
||||
FROM pg_operator o, pg_type lt, pg_type result
|
||||
WHERE o.oprkind='r' and o.oprleft = lt.oid
|
||||
AND o.oprresult = result.oid
|
||||
ORDER BY operand""")
|
||||
return result
|
||||
|
||||
# list all left-unary operators
|
||||
def list_left_unary_operator(pgcnx):
|
||||
result = pgcnx.query("""SELECT o.oprname AS left_unary,
|
||||
rt.typname AS operand, result.typname AS return_type
|
||||
FROM pg_operator o, pg_type rt, pg_type result
|
||||
WHERE o.oprkind='l' AND o.oprright = rt.oid
|
||||
AND o.oprresult = result.oid
|
||||
ORDER BY operand""")
|
||||
return result
|
||||
|
||||
# list all binary operators
|
||||
def list_binary_operator(pgcnx):
|
||||
result = pgcnx.query("""SELECT o.oprname AS binary_op,
|
||||
rt.typname AS right_opr, lt.typname AS left_opr,
|
||||
result.typname AS return_type
|
||||
FROM pg_operator o, pg_type rt, pg_type lt, pg_type result
|
||||
WHERE o.oprkind = 'b' AND o.oprright = rt.oid
|
||||
AND o.oprleft = lt.oid AND o.oprresult = result.oid""")
|
||||
return result
|
||||
|
||||
# returns the name, args and return type from all function of lang l
|
||||
def list_lang_func(pgcnx, l):
|
||||
result = pgcnx.query("""SELECT p.proname, p.pronargs, t.typname
|
||||
FROM pg_proc p, pg_language l, pg_type t
|
||||
WHERE p.prolang = l.oid AND p.prorettype = t.oid
|
||||
AND l.lanname = '%s'
|
||||
ORDER BY proname""" % l)
|
||||
return result
|
||||
|
||||
# lists all the aggregate functions and the type to which they can be applied
|
||||
def list_agg_func(pgcnx):
|
||||
result = pgcnx.query("""SELECT a.aggname, t.typname
|
||||
FROM pg_aggregate a, pg_type t
|
||||
WHERE a.aggbasetype = t.oid
|
||||
ORDER BY aggname, typname""")
|
||||
return result
|
||||
|
||||
# lists all the operator classes that can be used with each access method as
|
||||
# well as the operators that can be used with the respective operator classes
|
||||
def list_op_class(pgcnx):
|
||||
result = pgcnx.query("""SELECT am.amname, opc.opcname, opr.oprname
|
||||
FROM pg_am am, pg_amop amop, pg_opclass opc, pg_operator opr
|
||||
WHERE amop.amopid = am.oid and amop.amopclaid = opc.oid
|
||||
AND amop.amopopr = opr.oid order by amname, opcname, oprname""")
|
||||
return result
|
||||
|
||||
# demo function - runs all examples
|
||||
def demo(pgcnx):
|
||||
import sys, os
|
||||
save_stdout = sys.stdout
|
||||
sys.stdout = os.popen("more", "w")
|
||||
print "Listing simple indices ..."
|
||||
print list_simple_ind(pgcnx)
|
||||
print "Listing all attributes ..."
|
||||
print list_all_attr(pgcnx)
|
||||
print "Listing all user-defined base types ..."
|
||||
print list_user_base_type(pgcnx)
|
||||
print "Listing all left-unary operators defined ..."
|
||||
print list_left_unary_operator(pgcnx)
|
||||
print "Listing all right-unary operators defined ..."
|
||||
print list_right_unary_operator(pgcnx)
|
||||
print "Listing all binary operators ..."
|
||||
print list_binary_operator(pgcnx)
|
||||
print "Listing C external function linked ..."
|
||||
print list_lang_func(pgcnx, 'C')
|
||||
print "Listing C internal functions ..."
|
||||
print list_lang_func(pgcnx, 'internal')
|
||||
print "Listing SQL functions defined ..."
|
||||
print list_lang_func(pgcnx, 'sql')
|
||||
print "Listing 'aggregate functions' ..."
|
||||
print list_agg_func(pgcnx)
|
||||
print "Listing 'operator classes' ..."
|
||||
print list_op_class(pgcnx)
|
||||
del sys.stdout
|
||||
sys.stdout = save_stdout
|
||||
Loading…
Reference in New Issue