Column names that make joining tables more difficult

Query goal:

Find foreign keys where the name of the foreign key column and the corresponding primary key/unique column is different. Exclude foreign key columns that refer to the key of the same table because within each named table column names must be different. Simplify writing queries that have to join data from multiple base tables. If the columns that participate in the join condition have the same name, then one can use the USING syntax.

Notes about the query:

If the foreign key column name refers to a role, then there is no problem. Thus the query can give false positive results.

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:

If the difference is unintentional and minor, then change the names so that these would be identical. On the other hand, if the foreign key column name describes the role of the entity type in the context of the implemented relationship type, then no renaming is needed.

Data source:

system catalog only

SQL query:

Click on query to copy it

with fk as (select 
o.conname,
(select nspname from pg_namespace where oid=f.relnamespace) as foreign_schema,
f.relname as foreign_table,
f.oid as foreign_table_oid,
unnest(o.confkey) AS foreign_col,
(select nspname from pg_namespace where oid=c.relnamespace) as target_schema,
c.relname as target_table, 
c.oid as target_table_oid,
unnest(o.conkey) AS target_col
from pg_constraint o inner join pg_class c on c.oid = o.conrelid
inner join pg_class f on f.oid = o.confrelid 
where o.contype = 'f'),
fk_columns as (
select fk.conname, fk.foreign_schema, fk.foreign_table, a_foreign.attname as foreign_col, fk.target_schema, fk.target_table, a_target.attname as target_col
from fk inner join pg_attribute a_foreign on fk.foreign_col = a_foreign.attnum and fk.foreign_table_oid = a_foreign.attrelid and a_foreign.attisdropped = false
inner join pg_attribute a_target on fk.target_col = a_target.attnum and fk.target_table_oid = a_target.attrelid and a_target.attisdropped = false)
select *
from fk_columns
where ((foreign_schema<>target_schema) or (foreign_schema=target_schema and foreign_table<>target_table)) and foreign_col<>target_col
order by target_schema, target_table, conname;

Categories where the query belongs to

Category name	Category description
Comfortability of data management	Queries of this category provide information about the means that have been used to make the use or management of database more comfortable and thus, more efficient.
Naming	Queries of this category provide information about the style of naming.
Relationships between tables	Queries of this category provide information about how database tables are connected to each other and whether such connections have been explicitly defined and whether it has been done correctly.

Category name

Category description

Comfortability of data management

Queries of this category provide information about the means that have been used to make the use or management of database more comfortable and thus, more efficient.

Naming

Queries of this category provide information about the style of naming.

Relationships between tables

Queries of this category provide information about how database tables are connected to each other and whether such connections have been explicitly defined and whether it has been done correctly.

Reference materials for further reading

Reference
https://www.neilwithdata.com/join-using

Reference

https://www.neilwithdata.com/join-using