PostgreSQL/Postgre SQL/Declare Variable

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Using variable declaration options

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postgres=# -- Using variable declaration options postgres=# postgres=# CREATE FUNCTION example_function () RETURNS text AS " postgres"# DECLARE postgres"# postgres"# -- Declare a constant integer with a default value of 5. postgres"# five CONSTANT INTEGER := 5; postgres"# postgres"# -- Declare an integer with a default value of 100 that cannot be NULL. postgres"# ten INTEGER NOT NULL := 10; postgres"# postgres"# -- Declare a character with a default value of "a". postgres"# letter CHAR DEFAULT ""a""; postgres"# postgres"# BEGIN postgres"# return letter; postgres"# END; postgres"# " LANGUAGE "plpgsql"; CREATE FUNCTION postgres=# postgres=# select example_function ();

example_function

a

(1 row) postgres=# postgres=# drop function example_function (); DROP FUNCTION postgres=# postgres=#

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Variable Declarations

   <source lang="sql">

postgres=# -- Variable Declarations postgres=# postgres=# CREATE FUNCTION identifier () RETURNS int4 AS " postgres"# DECLARE postgres"# postgres"# -- Declare an integer. postgres"# subject_id INTEGER; postgres"# postgres"# -- Declare a variable length character. postgres"# book_title VARCHAR(10); postgres"# postgres"# -- Declare a floating point number. postgres"# book_price FLOAT; postgres"# postgres"# BEGIN postgres"# return 10; postgres"# END; postgres"# " LANGUAGE "plpgsql"; ERROR: function "identifier" already exists with same argument types postgres=# postgres=# select identifier();

identifier

        10

(1 row) postgres=# postgres=# drop function identifier(); DROP FUNCTION postgres=# postgres=#

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