PostgreSQL/Cursor/Declare Cursor

Opens a transaction, declares the cur_publishers cursor, and closes it

postgres=# CREATE TABLE "publishers" (
postgres(#      "id" integer NOT NULL,
postgres(#      "name" text,
postgres(#      "address" text,
postgres(#      Constraint "publishers_pkey" Primary Key ("id")
postgres(# );
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "publishers_pkey" for table "publishers"
CREATE TABLE
postgres=#
postgres=#
postgres=# insert into publishers values(150, "Can Press",  "29 Ave. Toronto, ON");
INSERT 0 1
postgres=# insert into publishers values(91,  "Henry Inc.", "115 Street New York, NY");
INSERT 0 1
postgres=# insert into publishers values(113, "O Inc.",     "101 St, Sebastopol, CA");
INSERT 0 1
postgres=# insert into publishers values(62,  "W Pubs",     "1515, New York");
INSERT 0 1
postgres=# insert into publishers values(105, "N Press",    "19 W, New York");
INSERT 0 1
postgres=# insert into publishers values(99,  "A Inc",      "375 St, New York");
INSERT 0 1
postgres=# insert into publishers values(101, "Z Inc",      "375 Ave, New York");
INSERT 0 1
postgres=# insert into publishers values(163, "M Press",    "PO Box 1215");
INSERT 0 1
postgres=# insert into publishers values(171, "B",          "16 W. 18th St. New York");
INSERT 0 1
postgres=# insert into publishers values(102, "P Inc",      "375 Hudson St, New York");
INSERT 0 1
postgres=# insert into publishers values(75,  "D Inc",      "1540 Broadway, New York");
INSERT 0 1
postgres=# insert into publishers values(65,  "H Pubs",     "10 E 53rd St, New York");
INSERT 0 1
postgres=# insert into publishers values(59,  "R Inc",      "1540 Broadway, New York");
INSERT 0 1
postgres=#
postgres=# select * from publishers;
 id  |    name    |         address
-----+------------+-------------------------
 150 | Can Press  | 29 Ave. Toronto, ON
  91 | Henry Inc. | 115 Street New York, NY
 113 | O Inc.     | 101 St, Sebastopol, CA
  62 | W Pubs     | 1515, New York
 105 | N Press    | 19 W, New York
  99 | A Inc      | 375 St, New York
 101 | Z Inc      | 375 Ave, New York
 163 | M Press    | PO Box 1215
 171 | B          | 16 W. 18th St. New York
 102 | P Inc      | 375 Hudson St, New York
  75 | D Inc      | 1540 Broadway, New York
  65 | H Pubs     | 10 E 53rd St, New York
  59 | R Inc      | 1540 Broadway, New York
(13 rows)
postgres=#
postgres=#
postgres=# --Opens a transaction, declares the cur_publishers cursor, and closes it:
postgres=#
postgres=# BEGIN;
BEGIN
postgres=# DECLARE cur_publishers CURSOR FOR SELECT * FROM publishers;
DECLARE CURSOR
postgres=# CLOSE cur_publishers;
CLOSE CURSOR
postgres=#
postgres=# drop table publishers;
DROP TABLE
postgres=#

Using cursor in transaction

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=# BEGIN;
BEGIN
postgres=# DECLARE cur_employee CURSOR FOR SELECT id, name FROM employee;
DECLARE CURSOR
postgres=# FETCH FORWARD 2 IN cur_employee;
 id |  name
----+--------
  1 | Jason
  2 | Robert
(2 rows)
postgres=# -- Fetch backwards in the cur_employee cursor:
postgres=#
postgres=# FETCH BACKWARD 3 IN cur_employee;
 id | name
----+-------
  1 | Jason
(1 row)
postgres=#
postgres=# END;
COMMIT
postgres=#
postgres=#
postgres=#
postgres=# drop table employee;
DROP TABLE
postgres=#
postgres=#