Goal Find optional composite foreign keys that do not have MATCH FULL specified. Without MATCH FULL the system will permit partial foreign key values
Notes The query considers only foreign key constraints that involve more than one column.
Type Problem detection Each row in the result could represent a flaw in the design
Reliability Medium Medium number of false-positive results
License MIT (opens in new tab)
Fixing Suggestion Drop the forein key constraint and recreate it with the MATCH FULL specification.
Data Source system catalog only
SQL Query 
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.confmatchtype<>'f' and o.contype = 'f' and cardinality(o.confkey)>1),
fk_grouped as (
select fk.conname, fk.foreign_schema, array_agg(fk.foreign_table || '.' || a_foreign.attname order by  a_foreign.attnum) as foreign_col, fk.target_schema, array_agg(fk.target_table  || '.' || a_target.attname  order by  a_target.attnum) as target_col, 
array_agg(a_target.attnotnull order by  a_target.attnum) as target_not_null 
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
group by fk.conname, fk.foreign_schema, fk.target_schema)
select conname, foreign_schema, foreign_col, target_schema, target_col
from fk_grouped 
where not (target_not_null @> array['t']::boolean[])
order by target_schema, target_col;

SQL statements that help generate fixes for the identified problem.

Fix Action #1
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.confmatchtype<>'f' and o.contype = 'f' and cardinality(o.confkey)>1),
fk_grouped as (
select fk.conname, fk.foreign_schema, array_agg(fk.foreign_table || '.' || a_foreign.attname order by  a_foreign.attnum) as foreign_col, fk.target_schema, fk.target_table, array_agg(fk.target_table  || '.' || a_target.attname  order by  a_target.attnum) as target_col, 
array_agg(a_target.attnotnull order by  a_target.attnum) as target_not_null 
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
group by fk.conname, fk.foreign_schema, fk.target_schema, fk.target_table)
SELECT format('ALTER TABLE %1$I.%2$I DROP CONSTRAINT %3$I;',  target_schema, target_table, conname) AS statements
from fk_grouped 
where not (target_not_null @> array['t']::boolean[])
order by target_schema, target_col;

Drop the constraint.

SQL Query to Generate FixDescription
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.confmatchtype<>'f' and o.contype = 'f' and cardinality(o.confkey)>1),
fk_grouped as (
select fk.conname, fk.foreign_schema, array_agg(fk.foreign_table || '.' || a_foreign.attname order by  a_foreign.attnum) as foreign_col, fk.target_schema, fk.target_table, array_agg(fk.target_table  || '.' || a_target.attname  order by  a_target.attnum) as target_col, 
array_agg(a_target.attnotnull order by  a_target.attnum) as target_not_null 
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
group by fk.conname, fk.foreign_schema, fk.target_schema, fk.target_table)
SELECT format('ALTER TABLE %1$I.%2$I DROP CONSTRAINT %3$I;',  target_schema, target_table, conname) AS statements
from fk_grouped 
where not (target_not_null @> array['t']::boolean[])
order by target_schema, target_col;
Drop the constraint.

Collections

This query belongs to the following collections:

Find problems automatically

Queries, that results point to problems in the database. Each query in the collection produces an initial assessment. However, a human reviewer has the final say as to whether there is a problem or not .

NameDescription
Find problems automaticallyQueries, that results point to problems in the database. Each query in the collection produces an initial assessment. However, a human reviewer has the final say as to whether there is a problem or not .

Categories

This query is classified under the following categories:

Missing data

Queries of this category provide information about missing data (NULLs) in a database.

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.

NameDescription
Missing dataQueries of this category provide information about missing data (NULLs) in a database.
Relationships between tablesQueries 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.