Prefer Polymorphism to If/Else or Switch/Case (2)

Query goal:

Find routines with multiple raise exception commands. Perhaps it has multiple tasks and it violates the separation of concerns and single responsibilities principles.

Notes about the query:

Refers to the column pg_proc.prokind and thus works starting from PostgreSQL 11. In the returned body of routine the query replaces each newline character with the line break (br) tag for the better readability in case the query result is displayed in a web browser. There could be multiple routines with the same name but with different parameters in the same schema (overloading). Thus, for the unique identification of the routine it is necessary to present also its parameters in addition to the schema name and routine name.

Query type:

Problem detection (Each row in the result could represent a flaw in the design)

Query reliability:

Low (Many false-positive results)

Query license:

MIT License

Fixing suggestion:

Create multiple triggers where each has a WHEN clause.

Data source:

INFORMATION_SCHEMA+system catalog

SQL query:

Click on query to copy it

SELECT 
  pg_namespace.nspname AS routine_schema, 
  pg_proc.proname AS routine_name, 
  pg_get_function_identity_arguments(pg_proc.oid) AS parameters,
  CASE WHEN pg_proc.prokind='f' THEN 'FUNCTION'
  WHEN pg_proc.prokind='p' THEN 'PROCEDURE'
  WHEN pg_proc.prokind='w' THEN 'WINDOW FUNCTION' END AS routine_type,
  regexp_replace(pg_get_functiondef(pg_proc.oid),'[\r\n]','<br>','g')  AS routine_src
FROM 
  pg_catalog.pg_proc, 
  pg_catalog.pg_namespace,
  pg_catalog.pg_language
WHERE 
  pg_proc.pronamespace = pg_namespace.oid 
  AND pg_proc.prolang = pg_language.oid 
  AND pg_language.lanname='plpgsql' 
  AND pg_proc.prokind<>'a' 
  AND pg_proc.proname NOT IN ('f_assume_you_must_use_files', 'f_check_format_comma_separated_list', 'f_check_password', 'f_default_value_with_no_match') 
  AND pg_get_functiondef(pg_proc.oid)~*'raise[[:space:]]+exception[[:space:]].+raise[[:space:]]+exception[[:space:]]'
 AND pg_namespace.nspname NOT IN (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL)
ORDER BY routine_schema, routine_name, parameters;

Categories where the query belongs to

Category name	Category description
Does not work in some earlier PostgreSQL version	Queries of this category provide information that was not available in some earlier PostgreSQL version
Triggers and rules	Queries of this category provide information about triggers and rules in a database.

Category name

Category description

Does not work in some earlier PostgreSQL version

Queries of this category provide information that was not available in some earlier PostgreSQL version

Triggers and rules

Queries of this category provide information about triggers and rules in a database.

Reference materials for further reading

Reference
https://en.wikipedia.org/wiki/Separation_of_concerns
The corresponding code smell in case of cleaning code is "G23: Prefer Polymorphism to If/Else or Switch/Case". (Robert C. Martin, Clean Code)

Reference

https://en.wikipedia.org/wiki/Separation_of_concerns

The corresponding code smell in case of cleaning code is "G23: Prefer Polymorphism to If/Else or Switch/Case". (Robert C. Martin, Clean Code)