SET DEFAULT compensatory action is unsuitable

Query goal:

Find foreign keys with SET DEFAULT compensatory action where the foreign key column does not have a default value. Compensatory actions cannot make changes that violate integrity constraints in a database. SET DEFAULT means that there shoud be a default value at the foreign key column.

Notes about the query:

Find foreign keys with SET DEFAULT compensating action that do not have a default value at the foreign key column. The default default is null. The query consider only simple foreign keys, i.e., foreign keys that involve only one column.

Query type:

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

Query reliability:

High (Few or no false-positive results)

Query license:

MIT License

Fixing suggestion:

Change the compensatory action or declare a default value to the foreign key column. In order to change the compensatory action one has to drop and recreate the foreign key constraint.

Data source:

INFORMATION_SCHEMA+system catalog

SQL query:

Click on query to copy it

WITH f AS (select (select nspname from pg_namespace where oid=f.relnamespace) as foreign_ns,
f.relname as foreign_table,
(select a.attname from pg_attribute a where a.attrelid = f.oid and a.attnum = o.confkey[1] and a.attisdropped = false) as foreign_colname,
(select nspname from pg_namespace where oid=c.relnamespace) as target_ns,
c.relname as target_table,
(select a.attname from pg_attribute a where a.attrelid = c.oid and a.attnum = o.conkey[1] and a.attisdropped = false) as target_colname,
o.confupdtype, o.confdeltype 
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')
SELECT foreign_ns, foreign_table, foreign_colname, target_ns, target_table, target_colname,
CASE WHEN confupdtype='c' THEN 'CASCADE'
WHEN confupdtype='r' THEN 'RESTRICT'
WHEN confupdtype='n' THEN 'SET NULL'
WHEN confupdtype='d' THEN 'SET DEFAULT'
ELSE 'NO ACTION' END AS on_update_behavior,
CASE WHEN confdeltype='c' THEN 'CASCADE'
WHEN confdeltype='r' THEN 'RESTRICT'
WHEN confdeltype='n' THEN 'SET NULL'
WHEN confdeltype='d' THEN 'SET DEFAULT'
ELSE 'NO ACTION' END AS on_delete_behavior
FROM f
WHERE (confupdtype='d' OR confdeltype='d') AND EXISTS (SELECT 1
FROM information_schema.columns AS c LEFT JOIN information_schema.column_domain_usage cdc ON 
c.table_schema=cdc.table_schema AND c.table_name=cdc.table_name AND c.column_name=cdc.column_name 
LEFT JOIN information_schema.domains d ON cdc.domain_schema=d.domain_schema AND cdc.domain_name=d.domain_name
WHERE  f.target_ns=c.table_schema AND f.target_table=c.table_name AND f.target_colname=c.column_name AND 
coalesce(c.column_default, domain_default) IS NULL)
ORDER BY target_ns, target_table, target_colname;

SQL statements for generating SQL statements that help us to fix the problem

SQL query	Description
WITH f AS (select o.conname, (select nspname from pg_namespace where oid=c.relnamespace) as target_ns, c.relname as target_table, (select a.attname from pg_attribute a where a.attrelid = c.oid and a.attnum = o.conkey[1] and a.attisdropped = false) as target_colname, o.confupdtype, o.confdeltype 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' and cardinality(o.conkey)=1) SELECT format('ALTER TABLE %1$I.%2$I DROP CONSTRAINT %3$I;', target_ns, target_table, conname) AS statements FROM f WHERE (confupdtype='d' OR confdeltype='d') AND EXISTS (SELECT 1 FROM information_schema.columns AS c LEFT JOIN information_schema.column_domain_usage cdc ON c.table_schema=cdc.table_schema AND c.table_name=cdc.table_name AND c.column_name=cdc.column_name LEFT JOIN information_schema.domains d ON cdc.domain_schema=d.domain_schema AND cdc.domain_name=d.domain_name WHERE f.target_ns=c.table_schema AND f.target_table=c.table_name AND f.target_colname=c.column_name AND coalesce(c.column_default, domain_default) IS NULL) ORDER BY target_ns, target_table, target_colname;	Drop the foreign key constraint.

SQL query

Description

WITH f AS (select 
o.conname,
(select nspname from pg_namespace where oid=c.relnamespace) as target_ns,
c.relname as target_table,
(select a.attname from pg_attribute a where a.attrelid = c.oid and a.attnum = o.conkey[1] and a.attisdropped = false) as target_colname,
o.confupdtype, o.confdeltype 
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' and cardinality(o.conkey)=1)
SELECT format('ALTER TABLE %1$I.%2$I DROP CONSTRAINT %3$I;', target_ns, target_table, conname) AS statements
FROM f
WHERE (confupdtype='d' OR confdeltype='d') AND EXISTS (SELECT 1
FROM information_schema.columns AS c LEFT JOIN information_schema.column_domain_usage cdc ON 
c.table_schema=cdc.table_schema AND c.table_name=cdc.table_name AND c.column_name=cdc.column_name 
LEFT JOIN information_schema.domains d ON cdc.domain_schema=d.domain_schema AND cdc.domain_name=d.domain_name
WHERE  f.target_ns=c.table_schema AND f.target_table=c.table_name AND f.target_colname=c.column_name AND 
coalesce(c.column_default, domain_default) IS NULL)
ORDER BY target_ns, target_table, target_colname;

Drop the foreign key constraint.

Collections where the query belongs to

Collection name	Collection description
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 .

Collection name

Collection description

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 .

Categories where the query belongs to

Category name	Category description
Compensating actions	Queries of this category provide information about compensating actions of foreign key constraints.
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

Compensating actions

Queries of this category provide information about compensating actions of foreign key constraints.

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.