Extending the Database: SQL Functions

test=> CREATE FUNCTION name_len(employees)
test-> RETURNS int4
test-> AS
test-> 'SELECT
test'> CASE WHEN $1.last_name = null THEN 0 ELSE
char_length($1.last_name) END
test'> + 1 +
test'> CASE WHEN $1.last_name = null THEN 0 ELSE
char_length($1.last_name) END
test'> AS name_length'
test-> LANGUAGE 'sql' \g
CREATE
test=> SELECT name_len(employees)
test-> FROM employees \g