Postgresql Server Programming

‫خدا‬ ‫نام‬ ‫به‬
‫اطلاعاتی‬ ‫بانک‬ ‫با‬ ‫آشنایی‬ ‫سمینار‬
PostgreSQL
‫دوم‬ ‫بخش‬
‫مشهد‬ ‫برق‬ ‫نیروی‬ ‫توزیع‬ ‫شرکت‬
‫پاییز‬۱۳۹۴

Common Table Expressions (CTE)
● Basic CTE , Writable CTE , Recursive CTE
●
‫نوع‬basic‫کارایی‬ ‫بردن‬ ‫بال‬ ‫یا‬ ‫کویری‬ ‫کردن‬ ‫خوانا‬ ‫جهت‬
  WITH
    T1 as ( Select * from table1  ),
    T2 as ( Select * from table2  )
  Select  T1.f1 , T2.f2  from  T1
    inner join T2  on ( T1.f1,T2.f1);
●
‫نوع‬writable!‫دیگر‬ ‫جدول‬ ‫در‬ ‫درج‬ ‫همزمان‬ ‫جدول‬ ‫یک‬ ‫های‬ ‫رکورد‬ ‫حذف‬ :
WITH t AS (
DELETE FROM ONLY logs_2011 WHERE log_ts < '20110301' RETURNING  *
)
INSERT INTO logs_2011_01_02 SELECT * FROM t;

Common Table Expressions
● Recursive statement
with recursive fib as (
    select 0 as a, 1 as b
    union all
    select b as a, a+b from fib where a < 100
) select a from fib;

Recursive CTE
id parent_id title
1 0 ‫دانشگاه‬
2 1 ‫ادبیات‬ ‫دانشکده‬
3 1 ‫مهندسی‬ ‫دانشکده‬
4 2 ‫فارسی‬ ‫ادبیات‬ ‫گروه‬
5 2 ‫مکانیک‬ ‫مهندسی‬ ‫گروه‬
6 4 ‫فارسی‬ ‫زبان‬
7 4 ‫تاریخ‬
8 5 ‫سیالت‬
9 5 ‫جامدات‬

Recursive CTE
title
‫دانشگاه‬
‫دانشگاه‬ -> ‫ادبیات‬ ‫دانشکده‬
‫دانشگاه‬ -> ‫مهندسی‬ ‫دانشکده‬
‫دانشگاه‬ -> ‫ادبیات‬ ‫دانشکده‬ -> ‫فارسی‬ ‫ادبیات‬ ‫گروه‬
‫دانشگاه‬ -> ‫مهندسی‬ ‫دانشکده‬ ->‫مکانیک‬ ‫مهندسی‬ ‫گروه‬
-> ‫ادبیات‬ ‫دانشکده‬ -> ‫فارسی‬ ‫ادبیات‬ ‫>-گروه‬ ‫فارسی‬ ‫زبان‬
‫دانشگاه‬ -> ‫ادبیات‬ ‫دانشکده‬ -> ‫فارسی‬ ‫ادبیات‬ ‫>-گروه‬ ‫تاریخ‬
-> ‫مهندسی‬ ‫دانشکده‬ -> ‫مکانیک‬ ‫مهندسی‬ ‫گروه‬ ->‫سیالت‬
-> ‫مهندسی‬ ‫دانشکده‬ ->‫مکانیک‬ ‫مهندسی‬ ‫گروه‬ ->‫جامدات‬

WITH Recursive
with recursive  tree ( id , parent_id  , _unit_name ) as
(
  select  u1.id , u1.parent_id , u1._name::text
    from university u1
  where parent_id = 0
  union all
  select u2.id,2.parent_id,u2._name || '>' ||t1._unit_name
    from university u2
    inner join tree t1 on t1.id = u2.parent_id
  )
  select  _unit_name from tree

Window functions
● row_number , avg , sum , rank
Select row_number() over(order by stno),stno from grades;
SELECT faculty,stno,grade,rank()
  OVER ( PARTITION BY faculty order by grade desc )
  FROM grades;
SELECT salary, sum(salary) OVER () FROM empsalary;
SELECT salary, sum(salary) OVER (ORDER BY salary)
  FROM empsalary;
SELECT sum(salary) OVER w, avg(salary) OVER w
  FROM empsalary
  WINDOW w AS (PARTITION BY depname ORDER BY salary DESC);

ARRAY datatype
● Integer integer[]→
● Varchar varchar[]→
● Json json[]→
● Text text[][]→
‫بعدی‬ ‫دو‬ ‫آرایه‬
Integer[3][3] : '{{1,2,3},{4,5,6},{7,8,9}}'

ARRAY datatype & Functions
INSERT INTO sal_emp
    VALUES ('Bill',
    '{10000, 10000, 10000, 10000}',
    '{{"meeting", "lunch"}, {"training", "presentation"}}');
INSERT INTO sal_emp   VALUES ('Bill',
    ARRAY[10000, 10000, 10000, 10000],
    ARRAY[['meeting', 'lunch'], ['training', 'presentation']]);
SELECT pay_by_quarter[3] FROM sal_emp;
SELECT array_prepend(1, ARRAY[2,3]);
SELECT array_cat(ARRAY[1,2], ARRAY[3,4]);
‫تبدیل‬‫سطر‬ ‫به‬ ‫آرایه‬:
Select unnest(ARRAY[1,2]) ;
Select * from unnest(ARRAY[1,2],ARRAY['foo','bar','baz'])

ARRAY operators
●
@> , >@@> , >@
– ARRAY[1,4,3] @> ARRAY[3,1]
●
< , >< , >
– ARRAY[1,2,3] < ARRAY[1,2,4]
●
&&&& (overlap)
– ARRAY[1,4,3] && ARRAY[2,1]
●
==
– ARRAY[1.1,2.1,3.1]::int[] = ARRAY[1,2,3]
●
||||
– ARRAY[1,2,3] || ARRAY[[4,5,6],[7,8,9]] , 3 || ARRAY[4,5,6]

JSON & JSONB datatype
Json : stores an exact copy of the input text , slow function
processing because of reparse of each execution.
Jsonb : faster process , store data as decompose binary.
SELECT '{"reading": 1.230e5}'::json, '{"reading": 1.230e5}'::jsonb;
json | jsonb
+
{"reading": 1.230e5} | {"reading": 0.00001230}
(1 row)

JSON & JSONB datatype
CREATE TABLE persons (person_id serial
PRIMARY KEY, relations jsonb);
Insert into persons(relations) values (
'{"name":"abbas","members":[
{"relation":"father" , "name":"ali"},
{"relation":"child" , "name":"mostafa"},
{"relation":"child" , "name":"mahdieh"}]}');

JSON Queries
  select   relations>'name' from persons;
  select   relations>'members' from persons;

  select   jsonb_extract_path(relations,'name')  from persons;
  select   jsonb_extract_path(relations,'members')  from persons;
  select   jsonb_extract_path(relations,'members')>1
     from persons;
  select   jsonb_extract_path(relations,'members')>1>'name'
     from persons;
  select   relations>'members'>1>'name'  from persons;

JSONB Operator
●
Jsonb Containment and Existence(@> , ?)
SELECT '[1, 2, 3]'::jsonb @> '[1, 3]'::jsonb;
SELECT ’{"product": "PostgreSQL", "version": 9.4,
"jsonb":true}’::jsonb @> ’{"version":9.4}’;
SELECT ’["foo", "bar", "baz"]’::jsonb ? ’bar’;
SELECT ’{"foo": "bar"}’::jsonb ? ’foo’;
SELECT ’{"foo": "bar"}’::jsonb ? ’bar’;

JSON Indexing
GIN : Generalized Inverted Index :
For full text search and jsonb
CREATE INDEX idxgin ON persons USING gin (relations);

Hstore datatype
● Create extension hstore;
● Hstore is a Key-value datatype
● Each key in an hstore is unique
– SELECT 'a=>1,a=>2'::hstore;
CREATE TABLE products (
     id serial PRIMARY KEY,
     name varchar(20),
     attributes hstore
   );
INSERT INTO products (name, attributes) VALUES (
    '‫برق‬ ‫,'تابلوی‬
    'length => "10",width => 20,Color=> "red"');
    '‫,'رایانه‬
    'processor=> "Intel",storage=>'250GB',ram=>"8GB"');
    '‫,'کتاب‬
    'author=>"Ali",pages=>368,price=>10000');

Hstore datatype
select  * from products
  where attributes>'pages' = '368';
select  attributes>'pages' from products
SELECT name, attributes>'pages'
   FROM products
   WHERE attributes ? 'pages'

Hstore Functions
● select * from each('a=>1,b=>2');
● Select hstore_to_matrix('a=>1,b=>2');
● Select hstore_to_array('a=>1,b=>2');
● Select svals('a=>1,b=>2') ;
● Select skeys('a=>1,b=>2');
● Select hstore('a', 'b');
● Select hstore(ARRAY['a','b'], ARRAY['1','2']);
● Select hstore(ROW(1,2));
● Select exist('a=>1','a');
● delete('a=>1,b=>2','b');
● delete('a=>1,b=>2','a=>4,b=>2'::hstore)

HStore add & update
● UPDATE tab SET h = h || hstore('c', '3');
● UPDATE tab SET h = delete(h, 'k1');

Full Text Search
● Tsvector
SELECT 'a fat cat sat on a mat and ate a fat rat'::tsvector;
SELECT 'a:1 fat:2 cat:3 sat:4 on:5 a:6 mat:7 and:8 ate:9 a:10 fat:11
rat:12'::tsvector;
● Tsquery
select to_tsquery( 'containment:*' );
Select to_tsquery( 'postgres:*' );
SELECT to_tsvector( 'postgraduate' ) @@ to_tsquery( 'postgres:*' );

Functions
●
. ‫تابع‬ ‫تعریف‬ ‫هنگام‬ ‫در‬ ‫ها‬ ‫متغییر‬ ‫نام‬ ‫به‬ ‫نیاز‬ ‫عدم‬
●
. ‫نها‬‌‫ه‬ ‫آ‬ ‫از‬ ‫استفاده‬ ‫هنگام‬ ‫در‬ ‫ها‬ ‫متغییر‬ ‫نام‬ ‫به‬ ‫نیاز‬ ‫عدم‬
●
. ‫آرایه‬ ‫بصورت‬ ‫ها‬ ‫پارامتر‬ ‫تعریف‬
●
‫و‬ ‫پایتون‬ ‫مثل‬ ‫ای‬ ‫پیشرفته‬ ‫نهای‬‌‫ه‬ ‫زبا‬ ‫تهای‬‌‫ه‬ ‫قابلی‬ ‫از‬ ‫استفاده‬
. ‫اسکریپت‬ ‫جاوا‬
●
)‫برگشتی‬ ‫و‬ ‫ورودی‬ ‫مقادیر‬ ‫نوع‬ ‫بودن‬ ‫نامشخص‬Pseudo-
Types(

Functions
CREATE OR REPLACE FUNCTION get_cities()
  RETURNS cities AS
'select * from cities;'
  LANGUAGE sql VOLATILE
CREATE OR REPLACE FUNCTION get_cities()
  RETURNS setof cities AS
'select * from cities;'
  LANGUAGE sql VOLATILE
select   get_cities();
select   * from  get_cities();
select   row_to_json(get_cities());
select   row_to_json(get_cities())>'name';

Functions
CREATE FUNCTION add(integer, integer) RETURNS integer
    AS 'select $1 + $2;'
    LANGUAGE SQL
    IMMUTABLE
    RETURNS NULL ON NULL INPUT;
CREATE OR REPLACE FUNCTION increment(i integer) RETURNS integer AS $$
        BEGIN
                RETURN i + 1;
        END;
$$ LANGUAGE plpgsql;
CREATE FUNCTION dup(in int, out f1 int, out f2 text)
    AS $$ SELECT $1, CAST($1 AS text) || ' is text' $$
    LANGUAGE SQL;
SELECT * FROM dup(42);
CREATE TYPE dup_result AS (f1 int, f2 text);
CREATE FUNCTION dup1(int) RETURNS dup_result
    AS $$ SELECT $1, CAST($1 AS text) || ' is text' $$
    LANGUAGE SQL;

Functions
CREATE OR REPLACE FUNCTION unnest_v(VARIADIC arr anyarray)
RETURNS SETOF anyelement AS $$
BEGIN
RETURN QUERY SELECT unnest(arr);
END;
$$ LANGUAGE plpgsql;
select unnest_v('11',2,3,4,7,8,9,10000,'400');

Python Functions
CREATE OR REPLACE FUNCTION list_incoming_files()
RETURNS SETOF text AS
$$
import os
return os.listdir('/home/baniasadi')
$$
LANGUAGE 'plpython2u' VOLATILE SECURITY DEFINER;

Python Functions
CREATE OR REPLACE FUNCTION postgresql_help_search
                                       (param_search     text)
RETURNS text AS
$$
  import urllib, re
  response = urllib.urlopen(
  'http://www.postgresql.org/search/?u=%2Fdocs%2Fcurrent%2F&q=' +
   param_search)
  raw_html = response.read()
  result = raw_html[raw_html.find("<! docbot goes here >") :
  raw_html.find("<! pgContentWrap >") 1]
  result = re.sub('<[^<]+?>', '', result).strip()
  return result
$$
LANGUAGE plpython2u SECURITY DEFINER STABLE;

Java Script Functions
CREATE OR REPLACE FUNCTION validate_email(email text)
returns boolean as
$$
var re = /S+@S+.S+/;
return re.test(email);
$$ LANGUAGE plv8 IMMUTABLE STRICT;

Java Script Functions
CREATE OR REPLACE FUNCTION get_citiy(city_name text)
RETURNS setof cities AS
$BODY$
var plan = plv8.prepare( 'SELECT * FROM cities where name = $1 ',['text'] ) ;
var cursor = plan.cursor([city_name]);
row = cursor.fetch();
cursor.close();
plan.free();
return row;
$BODY$
LANGUAGE plv8 VOLATILE
COST 100;
ALTER FUNCTION get_citiy(city_name text)
OWNER TO postgres;
select get_citiy('mashhad');

‫دوم‬ ‫بخش‬ ‫پایان‬
‫شما‬ ‫توجه‬ ‫از‬ ‫تشکر‬ ‫با‬
‫مقدم‬ ‫اسدی‬ ‫بنی‬ ‫عباس‬
baniasadi@meedc.net
‫پاک‬ ‫دست‬ ‫محمد‬
m.dastpak@meedc.net

Postgresql Server Programming

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