Find all non-identifying relationships where the foreign key (a set of columns) is a subset of a uniqueness constraint (primary key, unique, or exclude constraint).
Type
General (Overview of some aspect of the database.)
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,
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,
o.conkey AS target_col,
CASE WHEN o.confupdtype='a' THEN 'NO ACTION'
WHEN o.confupdtype='r' THEN 'RESTRICT'
WHEN o.confupdtype='c' THEN 'CASCADE'
WHEN o.confupdtype='n' THEN 'SET NULL'
WHEN o.confupdtype='d' THEN 'SET DEFAULT' END AS on_update,
CASE WHEN o.confdeltype='a' THEN 'NO ACTION'
WHEN o.confdeltype='r' THEN 'RESTRICT'
WHEN o.confdeltype='c' THEN 'CASCADE'
WHEN o.confdeltype='n' THEN 'SET NULL'
WHEN o.confdeltype='d' THEN 'SET DEFAULT' END AS on_delete
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_unnest as (select conname, foreign_schema, foreign_table, foreign_table_oid, foreign_col, foreign_col_num, target_schema, target_table, target_table_oid, target_col, target_col_num, ordin, on_update, on_delete
from fk, unnest(fk.foreign_col, fk. target_col) with ordinality as f(foreign_col_num, target_col_num, ordin)),
fk_with_names as (select conname, foreign_schema, foreign_table, array_agg(a_foreign.attname order by ordin) as foreign_col, target_schema, target_table, array_agg(a_target.attname order by ordin) as target_col, on_update, on_delete
from fk_unnest fk inner join pg_attribute a_foreign on fk.foreign_col_num = 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_num = a_target.attnum and fk.target_table_oid = a_target.attrelid and a_target.attisdropped = false
group by conname, foreign_schema, foreign_table, target_schema, target_table,on_update, on_delete, target_col),
uq as (select
(select nspname from pg_namespace where oid=c.relnamespace) as target_schema,
c.relname as target_table,
c.oid as target_table_oid,
o.conkey AS target_col,
o.conname,
CASE
WHEN o.contype='p' THEN 'PRIMARY KEY'
WHEN o.contype='u' THEN 'UNIQUE'
WHEN o.contype='x' THEN 'EXCLUDE'
END AS contype
from pg_constraint o inner join pg_class c on c.oid = o.conrelid
where o.contype in ('p','u','x')),
uq_unnest as (select target_schema, target_table, conname, contype, target_table_oid, target_col, target_col_num, ordin
from uq, unnest(uq.target_col) with ordinality as f(target_col_num, ordin)),
uq_with_names as (select target_schema, target_table, conname, contype, array_agg(CASE WHEN a_target.attname IS NOT NULL THEN a_target.attname ELSE 'something' END order by ordin) as target_col
from uq_unnest uq left join pg_attribute a_target on uq.target_col_num = a_target.attnum and uq.target_table_oid = a_target.attrelid and a_target.attisdropped = false
left join pg_type AS t_target ON a_target.atttypid=t_target.oid
WHERE a_target.attnotnull = true
OR t_target.typnotnull=true
OR (a_target.attnotnull IS NULL AND t_target.typnotnull IS NULL)
group by target_schema, target_table, conname, contype)
select fk.conname, fk.foreign_schema, fk.foreign_table, fk.foreign_col, fk.target_schema, fk.target_table, fk.target_col, fk.on_update, fk.on_delete, uq.target_col as target_uq_col, contype AS target_uq_type
from fk_with_names as fk, uq_with_names as uq
where fk.target_schema=uq.target_schema
and fk.target_table=uq.target_table
and fk.target_col <@ uq.target_col
order by fk.target_schema, fk.target_table, fk.conname;
Collections
This query belongs to the following collections:
Name
Description
Find problems about integrity constraints
A selection of queries that return information about the state of integrity constraints in the datadabase. Contains all the types of queries - problem detection, software measure, and general overview
Find problems by overview
Queries that results point to different aspects of database that might have problems. A human reviewer has to decide based on the results as to whether there are problems or not .
Categories
This query is classified under the following categories:
Name
Description
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.
Uniqueness
Queries of this category provide information about uniqueness constraints (PRIMARY KEY, UNIQUE, EXCLUDE) as well as unique indexes.