PostgreSQL/Insert Delete Update/Update — различия между версиями

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Текущая версия на 10:14, 26 мая 2010

A simple UPDATE: change one cell

postgres=#
postgres=#
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=# -- A simple UPDATE
postgres=#
postgres=# SELECT name FROM employee WHERE id = 1;
 name
-------
 Jason
(1 row)
postgres=#
postgres=# UPDATE employee SET name = "newName" WHERE id = 1;
UPDATE 1
postgres=#
postgres=# SELECT name FROM employee WHERE id = 1;
  name
---------
 newName
(1 row)
postgres=#
postgres=#
postgres=#
postgres=# drop table employee;
DROP TABLE
postgres=#



Update a single row

postgres=#
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=#
postgres=# UPDATE employee SET id = 116 WHERE id = 1;
UPDATE 1
postgres=# SELECT * FROM employee WHERE id = 1;
 id | name | salary | start_date | city | region
----+------+--------+------------+------+--------
(0 rows)
postgres=#
postgres=#
postgres=#
postgres=#
postgres=#
postgres=# drop table employee;
DROP TABLE
postgres=#



Update in a slice

postgres=#
postgres=#
postgres=# CREATE TABLE sal_emp (
postgres(#    name            text,
postgres(#    pay_by_quarter  integer[],
postgres(#    schedule        text[][]
postgres(# );
CREATE TABLE
postgres=#
postgres=# INSERT INTO sal_emp
postgres-#    VALUES ("Bill",
postgres(#    ARRAY[10000, 10000, 10000, 10000],
postgres(#    ARRAY[["meeting", "lunch"], ["training", "presentation"]]);
INSERT 0 1
postgres=#
postgres=# INSERT INTO sal_emp
postgres-#    VALUES ("Carol",
postgres(#    ARRAY[20000, 25000, 25000, 25000],
postgres(#    ARRAY[["breakfast", "consulting"], ["meeting", "lunch"]]);
INSERT 0 1
postgres=#
postgres=# SELECT * FROM sal_emp;
 name  |      pay_by_quarter       |                 schedule
-------+---------------------------+-------------------------------------------
 Bill  | {10000,10000,10000,10000} | {{meeting,lunch},{training,presentation}}
 Carol | {20000,25000,25000,25000} | {{breakfast,consulting},{meeting,lunch}}
(2 rows)
postgres=#
postgres=# -- Update in a slice:
postgres=#
postgres=# UPDATE sal_emp SET pay_by_quarter[1:2] = "{27000,27000}" WHERE name = "Carol";
UPDATE 1
postgres=#
postgres=# select * from sal_emp;
 name  |      pay_by_quarter       |                 schedule
-------+---------------------------+-------------------------------------------
 Bill  | {10000,10000,10000,10000} | {{meeting,lunch},{training,presentation}}
 Carol | {27000,27000,25000,25000} | {{breakfast,consulting},{meeting,lunch}}
(2 rows)
postgres=#
postgres=# drop table sal_emp;
DROP TABLE
postgres=#
postgres=#



Update two columns in one single statement

postgres=#
postgres=# CREATE TABLE products (
postgres(#    product_no integer,
postgres(#    name text,
postgres(#    price numeric
postgres(# );
CREATE TABLE
postgres=#
postgres=# INSERT INTO products (product_no, name, price) VALUES (1, "Java", 1234);
INSERT 0 1
postgres=# INSERT INTO products (product_no, name, price) VALUES (2, "SQL Server", 3421);
INSERT 0 1
postgres=# INSERT INTO products (product_no, name, price) VALUES (3, "Oracle", 7623);
INSERT 0 1
postgres=# INSERT INTO products (product_no, name, price) VALUES (4, "DB2", 9874);
INSERT 0 1
postgres=# INSERT INTO products (product_no, name, price) VALUES (5, "Access", 5);
INSERT 0 1
postgres=#
postgres=#
postgres=# select * from products;
 product_no |    name    | price
------------+------------+-------
          1 | Java       |  1234
          2 | SQL Server |  3421
          3 | Oracle     |  7623
          4 | DB2        |  9874
          5 | Access     |     5
(5 rows)
postgres=#
postgres=# UPDATE products SET product_no = 999, name = "new Name", price = 1 WHERE price > 0;
UPDATE 5
postgres=#
postgres=# select * from products;
 product_no |   name   | price
------------+----------+-------
        999 | new Name |     1
        999 | new Name |     1
        999 | new Name |     1
        999 | new Name |     1
        999 | new Name |     1
(5 rows)
postgres=#
postgres=# drop table products;
DROP TABLE
postgres=#
postgres=#



Updating entire columns

postgres=#
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=# -- Updating entire columns
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=# UPDATE employee SET salary = (salary * 2);
UPDATE 9
postgres=#
postgres=# SELECT * FROM employee;
 id |  name  | salary | start_date |   city    | region
----+--------+--------+------------+-----------+--------
  1 | Jason  |  80840 | 1994-02-01 | New York  | W
  2 | Robert |  28840 | 1995-01-02 | Vancouver | N
  3 | Celia  |  48040 | 1996-12-03 | Toronto   | W
  4 | Linda  |  81240 | 1997-11-04 | New York  | N
  5 | David  | 160052 | 1998-10-05 | Vancouver | W
  6 | James  | 140120 | 1999-09-06 | Toronto   | N
  7 | Alison | 181240 | 2000-08-07 | New York  | W
  8 | Chris  |  52040 | 2001-07-08 | Vancouver | N
  9 | Mary   | 120040 | 2002-06-09 | Toronto   | W
(9 rows)
postgres=#
postgres=#
postgres=#
postgres=# drop table employee;
DROP TABLE
postgres=#



Updating Several Columns

postgres=#
postgres=#
postgres=# CREATE TABLE employee (
postgres(#     ID         int,
postgres(#     name       varchar(40),
postgres(#     salary     real,
postgres(#     start_date date,
postgres(#     city       varchar(100),
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=# -- Updating Several Columns
postgres=#
postgres=# UPDATE employee
postgres-#         SET name = "O\"Reilly",
postgres-#             city = "newCity" || " and new town"
postgres-#         WHERE id = 1;
UPDATE 1
postgres=#
postgres=# SELECT * FROM employee WHERE id = 1;
 id |   name   | salary | start_date |         city         | region
----+----------+--------+------------+----------------------+--------
  1 | O"Reilly |  40420 | 1994-02-01 | newCity and new town | W
(1 row)
postgres=#
postgres=#
postgres=#
postgres=# drop table employee;
DROP TABLE
postgres=#



Using expression in update statement

postgres=#
postgres=# CREATE TABLE products (
postgres(#    product_no integer,
postgres(#    name text,
postgres(#    price numeric
postgres(# );
CREATE TABLE
postgres=#
postgres=# INSERT INTO products (product_no, name, price) VALUES (1, "Java", 1234);
INSERT 0 1
postgres=# INSERT INTO products (product_no, name, price) VALUES (2, "SQL Server", 3421);
INSERT 0 1
postgres=# INSERT INTO products (product_no, name, price) VALUES (3, "Oracle", 7623);
INSERT 0 1
postgres=# INSERT INTO products (product_no, name, price) VALUES (4, "DB2", 9874);
INSERT 0 1
postgres=# INSERT INTO products (product_no, name, price) VALUES (5, "Access", 5);
INSERT 0 1
postgres=#
postgres=#
postgres=# select * from products;
 product_no |    name    | price
------------+------------+-------
          1 | Java       |  1234
          2 | SQL Server |  3421
          3 | Oracle     |  7623
          4 | DB2        |  9874
          5 | Access     |     5
(5 rows)
postgres=#
postgres=# UPDATE products SET price = price * 1.10;
UPDATE 5
postgres=#
postgres=# select * from products;
 product_no |    name    |  price
------------+------------+----------
          1 | Java       |  1357.40
          2 | SQL Server |  3763.10
          3 | Oracle     |  8385.30
          4 | DB2        | 10861.40
          5 | Access     |     5.50
(5 rows)
postgres=#
postgres=# drop table products;
DROP TABLE
postgres=#
postgres=#



Using UPDATE with several Employees

postgres=#
postgres=#
postgres=# create table job(
postgres(#     ID          int,
postgres(#     title       varchar (10));
CREATE TABLE
postgres=#
postgres=#
postgres=# insert into job(ID, title) values(1,"Developer");
INSERT 0 1
postgres=# insert into job(ID, title) values(2,"Tester");
INSERT 0 1
postgres=# insert into job(ID, title) values(3,"Designer");
INSERT 0 1
postgres=# insert into job(ID, title) values(4,"Programmer");
INSERT 0 1
postgres=#
postgres=# select * from job;
 id |   title
----+------------
  1 | Developer
  2 | Tester
  3 | Designer
  4 | Programmer
(4 rows)
postgres=#
postgres=#
postgres=#
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 UPDATE with several Employees
postgres=#
postgres=# UPDATE employee
postgres-#         SET salary = salary + 100
postgres-#         FROM job
postgres-#         WHERE job.id = employee.id;
UPDATE 4
postgres=#
postgres=# select * from employee;
 id |  name  | salary | start_date |   city    | region
----+--------+--------+------------+-----------+--------
  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
  1 | Jason  |  40520 | 1994-02-01 | New York  | W
  2 | Robert |  14520 | 1995-01-02 | Vancouver | N
  3 | Celia  |  24120 | 1996-12-03 | Toronto   | W
  4 | Linda  |  40720 | 1997-11-04 | New York  | N
(9 rows)
postgres=#
postgres=#
postgres=# drop table job;
DROP TABLE
postgres=# drop table employee;
DROP TABLE
postgres=#



Using user defined function to update table data

postgres=# CREATE TABLE emp (
postgres(#    name        text,
postgres(#    salary      numeric,
postgres(#    age         integer,
postgres(#    cubicle     point
postgres(# );
CREATE TABLE
postgres=#
postgres=# insert into emp (salary) values(100);
INSERT 0 1
postgres=# insert into emp (salary) values(200);
INSERT 0 1
postgres=# insert into emp (salary) values(300);
INSERT 0 1
postgres=#
postgres=# CREATE FUNCTION double_salary(emp) RETURNS numeric AS $$
postgres$#    SELECT $1.salary * 2 AS salary;
postgres$# $$ LANGUAGE SQL;
CREATE FUNCTION
postgres=#
postgres=# SELECT name, double_salary(ROW(name, salary*1.1, age, cubicle)) AS dream
postgres-#    FROM emp;
 name | dream
------+-------
      | 220.0
      | 440.0
      | 660.0
(3 rows)
postgres=#
postgres=# drop function double_salary(emp);
DROP FUNCTION
postgres=# drop table emp;
DROP TABLE
postgres=#
postgres=#