PostgreSQL/Postgre SQL/Set Value
Using select into to set variable value
postgres=#
postgres=# CREATE TABLE "editions" (
postgres(# "isbn" text NOT NULL,
postgres(# "book_id" integer,
postgres(# "edition" integer,
postgres(# "publisher_id" integer,
postgres(# "publication" date,
postgres(# "type" character(1),
postgres(# CONSTRAINT "integrity" CHECK (((book_id NOTNULL) AND (edition NOTNULL))),
postgres(# Constraint "pkey" Primary Key ("isbn")
postgres(# );
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "pkey" for table "editions"
CREATE TABLE
postgres=#
postgres=# insert into editions value("039480001X", 1608, 1, 59, "1957-03-01", "h");
postgres=# insert into editions value("0451160916", 7808, 1, 75, "1981-08-01", "p");
postgres=# insert into editions value("0394800753", 1590, 1, 59, "1949-03-01", "p");
postgres=# insert into editions value("0590445065", 25908, 1, 150, "1987-03-01", "p");
postgres=# insert into editions value("0694003611", 1501, 1, 65, "1947-03-04", "p");
postgres=# insert into editions value("0679803335", 1234, 1, 102, "1922-01-01", "p");
postgres=# insert into editions value("0760720002", 190, 1, 91, "1868-01-01", "p");
postgres=# insert into editions value("0394900014", 1608, 1, 59, "1957-01-01", "p");
postgres=# insert into editions value("0385121679", 7808, 2, 75, "1993-10-01", "h");
postgres=# insert into editions value("1885418035", 156, 1, 163, "1995-03-28", "p");
postgres=# insert into editions value("0929605942", 156, 2, 171, "1998-12-01", "p");
postgres=# insert into editions value("0441172717", 4513, 2, 99, "1998-09-01", "p");
postgres=# insert into editions value("044100590X", 4513, 3, 99, "1999-10-01", "h");
postgres=# insert into editions value("0451457994", 4267, 3, 101, "2000-09-12", "p");
postgres=# insert into editions value("0451198492", 4267, 3, 101, "1999-10-01", "h");
postgres=# insert into editions value("0823015505", 2038, 1, 62, "1958-01-01", "p");
postgres=# insert into editions value("0596000855", 41473, 2, 113, "2001-03-01", "p");
postgres=#
postgres=# select * from editions;
isbn | book_id | edition | publisher_id | publication | type
------+---------+---------+--------------+-------------+------
(0 rows)
postgres=#
postgres=#
postgres=#
postgres=# CREATE TABLE "stock" (
postgres(# "isbn" text NOT NULL,
postgres(# "cost" numeric(5,2),
postgres(# "retail" numeric(5,2),
postgres(# "stock" integer,
postgres(# Constraint "stock_pkey" Primary Key ("isbn")
postgres(# );
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "stock_pkey" for table "stock"
CREATE TABLE
postgres=#
postgres=#
postgres=# insert into stock values ("0385121679", 29.00, 36.95, 65);
INSERT 0 1
postgres=# insert into stock values ("039480001X", 30.00, 32.95, 31);
INSERT 0 1
postgres=# insert into stock values ("0394900014", 23.00, 23.95, 0);
INSERT 0 1
postgres=# insert into stock values ("044100590X", 36.00, 45.95, 89);
INSERT 0 1
postgres=# insert into stock values ("0441172717", 17.00, 21.95, 77);
INSERT 0 1
postgres=# insert into stock values ("0451160916", 24.00, 28.95, 22);
INSERT 0 1
postgres=# insert into stock values ("0451198492", 36.00, 46.95, 0);
INSERT 0 1
postgres=# insert into stock values ("0451457994", 17.00, 22.95, 0);
INSERT 0 1
postgres=# insert into stock values ("0590445065", 23.00, 23.95, 10);
INSERT 0 1
postgres=# insert into stock values ("0679803335", 20.00, 24.95, 18);
INSERT 0 1
postgres=# insert into stock values ("0694003611", 25.00, 28.95, 50);
INSERT 0 1
postgres=# insert into stock values ("0760720002", 18.00, 23.95, 28);
INSERT 0 1
postgres=# insert into stock values ("0823015505", 26.00, 28.95, 16);
INSERT 0 1
postgres=# insert into stock values ("0929605942", 19.00, 21.95, 25);
INSERT 0 1
postgres=# insert into stock values ("1885418035", 23.00, 24.95, 77);
INSERT 0 1
postgres=# insert into stock values ("0394800753", 16.00, 16.95, 4);
INSERT 0 1
postgres=#
postgres=# select * FROM stock;
isbn | cost | retail | stock
------------+-------+--------+-------
0385121679 | 29.00 | 36.95 | 65
039480001X | 30.00 | 32.95 | 31
0394900014 | 23.00 | 23.95 | 0
044100590X | 36.00 | 45.95 | 89
0441172717 | 17.00 | 21.95 | 77
0451160916 | 24.00 | 28.95 | 22
0451198492 | 36.00 | 46.95 | 0
0451457994 | 17.00 | 22.95 | 0
0590445065 | 23.00 | 23.95 | 10
0679803335 | 20.00 | 24.95 | 18
0694003611 | 25.00 | 28.95 | 50
0760720002 | 18.00 | 23.95 | 28
0823015505 | 26.00 | 28.95 | 16
0929605942 | 19.00 | 21.95 | 25
1885418035 | 23.00 | 24.95 | 77
0394800753 | 16.00 | 16.95 | 4
(16 rows)
postgres=#
postgres=# drop function stock_amount(integer, integer);
DROP FUNCTION
postgres=#
postgres=# -- Using the IF/THEN statement
postgres=#
postgres=# CREATE FUNCTION stock_amount (integer, integer) RETURNS integer AS "
postgres"# DECLARE
postgres"# -- Declare aliases for function arguments.
postgres"# b_id ALIAS FOR $1;
postgres"# b_edition ALIAS FOR $2;
postgres"# -- Declare variable to store the ISBN number.
postgres"# b_isbn TEXT;
postgres"# -- Declare variable to store the stock amount.
postgres"# stock_amount INTEGER;
postgres"# BEGIN
postgres"# SELECT INTO b_isbn isbn FROM editions WHERE
postgres"# book_id = b_id AND edition = b_edition;
postgres"#
postgres"# IF b_isbn IS NULL THEN
postgres"# RETURN -1;
postgres"# END IF;
postgres"#
postgres"# SELECT INTO stock_amount stock FROM stock WHERE isbn = b_isbn;
postgres"#
postgres"# RETURN stock_amount;
postgres"# END;
postgres"# " LANGUAGE "plpgsql";
CREATE FUNCTION
postgres=#
postgres=#
postgres=# SELECT stock_amount(7808,1);
stock_amount
--------------
-1
(1 row)
postgres=#
postgres=# drop table stock;
DROP TABLE
postgres=#
postgres=#
Using SELECT INTO with multiple columns
postgres=# CREATE TABLE employee (
postgres(# ID int,
postgres(# name varchar(10),
postgres(# salary real,
postgres(# start_date date,
postgres(# city varchar(10),
postgres(# region char(1)
postgres(# );
CREATE TABLE
postgres=#
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (1, "Jason", 40420, "02/01/94", "New York", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (2, "Robert",14420, "01/02/95", "Vancouver","N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (3, "Celia", 24020, "12/03/96", "Toronto", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (4, "Linda", 40620, "11/04/97", "New York", "N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (5, "David", 80026, "10/05/98", "Vancouver","W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (6, "James", 70060, "09/06/99", "Toronto", "N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (7, "Alison",90620, "08/07/00", "New York", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (8, "Chris", 26020, "07/08/01", "Vancouver","N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (9, "Mary", 60020, "06/09/02", "Toronto", "W");
INSERT 0 1
postgres=#
postgres=# select * from employee;
id | name | salary | start_date | city | region
----+--------+--------+------------+-----------+--------
1 | Jason | 40420 | 1994-02-01 | New York | W
2 | Robert | 14420 | 1995-01-02 | Vancouver | N
3 | Celia | 24020 | 1996-12-03 | Toronto | W
4 | Linda | 40620 | 1997-11-04 | New York | N
5 | David | 80026 | 1998-10-05 | Vancouver | W
6 | James | 70060 | 1999-09-06 | Toronto | N
7 | Alison | 90620 | 2000-08-07 | New York | W
8 | Chris | 26020 | 2001-07-08 | Vancouver | N
9 | Mary | 60020 | 2002-06-09 | Toronto | W
(9 rows)
postgres=#
postgres=# -- Using SELECT INTO with multiple columns
postgres=#
postgres=# CREATE FUNCTION get_data (integer) RETURNS text AS "
postgres"# DECLARE
postgres"#
postgres"# -- Declare aliases for user input.
postgres"# e_id ALIAS FOR $1;
postgres"#
postgres"# -- Declare variables to hold the customer name.
postgres"# fname TEXT;
postgres"# cityname TEXT;
postgres"#
postgres"# BEGIN
postgres"# SELECT INTO fname, cityname
postgres"# name, city
postgres"# FROM employee WHERE id = e_id;
postgres"#
postgres"# -- Return the name.
postgres"# RETURN fname || "" "" || cityname;
postgres"#
postgres"# END;
postgres"# " LANGUAGE "plpgsql";
CREATE FUNCTION
postgres=#
postgres=# SELECT get_data(1);
get_data
----------------
Jason New York
(1 row)
postgres=#
postgres=#
postgres=# drop function get_data(integer);
DROP FUNCTION
postgres=# drop table employee;
DROP TABLE
postgres=#
postgres=#
Using the SELECT INTO statement
postgres=# CREATE TABLE employee (
postgres(# ID int,
postgres(# name varchar(10),
postgres(# salary real,
postgres(# start_date date,
postgres(# city varchar(10),
postgres(# region char(1)
postgres(# );
CREATE TABLE
postgres=#
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (1, "Jason", 40420, "02/01/94", "New York", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (2, "Robert",14420, "01/02/95", "Vancouver","N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (3, "Celia", 24020, "12/03/96", "Toronto", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (4, "Linda", 40620, "11/04/97", "New York", "N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (5, "David", 80026, "10/05/98", "Vancouver","W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (6, "James", 70060, "09/06/99", "Toronto", "N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (7, "Alison",90620, "08/07/00", "New York", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (8, "Chris", 26020, "07/08/01", "Vancouver","N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (9, "Mary", 60020, "06/09/02", "Toronto", "W");
INSERT 0 1
postgres=#
postgres=# select * from employee;
id | name | salary | start_date | city | region
----+--------+--------+------------+-----------+--------
1 | Jason | 40420 | 1994-02-01 | New York | W
2 | Robert | 14420 | 1995-01-02 | Vancouver | N
3 | Celia | 24020 | 1996-12-03 | Toronto | W
4 | Linda | 40620 | 1997-11-04 | New York | N
5 | David | 80026 | 1998-10-05 | Vancouver | W
6 | James | 70060 | 1999-09-06 | Toronto | N
7 | Alison | 90620 | 2000-08-07 | New York | W
8 | Chris | 26020 | 2001-07-08 | Vancouver | N
9 | Mary | 60020 | 2002-06-09 | Toronto | W
(9 rows)
postgres=#
postgres=# -- Using the SELECT INTO statement
postgres=#
postgres=# CREATE FUNCTION get_id (text) RETURNS integer AS "
postgres"# DECLARE
postgres"# -- Declare aliases for user input.
postgres"# f_name ALIAS FOR $1;
postgres"# e_id INTEGER;
postgres"# BEGIN
postgres"# SELECT INTO e_id id FROM employee WHERE name = f_name;
postgres"# -- Return the ID number.
postgres"# RETURN e_id;
postgres"# END;
postgres"# " LANGUAGE "plpgsql";
CREATE FUNCTION
postgres=#
postgres=# select get_id("Mary");
get_id
--------
9
(1 row)
postgres=#
postgres=# drop function get_id (text);
DROP FUNCTION
postgres=# drop table employee;
DROP TABLE
postgres=#