Default is NULL

Query goal:

Find all tables where default value is NULL. NULL is the marker that denotes missing value. Implicitly all columns that do not have a default value have the default NULL. There is no need to specify such default value.

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:

Drop the default value.

Data source:

INFORMATION_SCHEMA only

SQL query:

Click on query to copy it

SELECT c.table_schema, t.table_type, c.table_name, c.column_name,  c.data_type, c.domain_schema, c.domain_name, c.column_default, domain_default
FROM information_schema.columns AS c LEFT JOIN information_schema.domains d USING (domain_schema, domain_name)
INNER JOIN INFORMATION_SCHEMA.tables AS t  USING (table_schema, table_name)
WHERE c.table_schema NOT IN (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL) 
AND (column_default IS NOT NULL OR domain_default IS NOT NULL)
AND (c.column_default~'^NULL::'
OR d.domain_default~'^NULL::')
ORDER BY t.table_type, c.table_schema, c.table_name, c.ordinal_position;

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

SQL query	Description
SELECT format('ALTER %4$s TABLE %1$I.%2$I ALTER COLUMN %3$I DROP DEFAULT;', A.table_schema, A.table_name, A.column_name, CASE WHEN B.table_type='FOREIGN' THEN table_type END) AS statements FROM information_schema.columns A INNER JOIN information_schema.schemata S ON A.table_schema=S.schema_name INNER JOIN information_schema.tables B USING (table_schema, table_name) WHERE A.column_default~'^NULL::' AND (A.table_schema = 'public' OR S.schema_owner<>'postgres') ORDER BY A.table_schema, A.table_name, A.column_name;	Drop the default that is directly associated with the column.
SELECT format('ALTER DOMAIN %1$I.%2$I DROP DEFAULT;', D.domain_schema, D.domain_name) AS statements FROM information_schema.domains D INNER JOIN information_schema.schemata S ON D.domain_schema=S.schema_name WHERE D.domain_default~'^NULL::' AND (D.domain_schema = 'public' OR S.schema_owner<>'postgres') ORDER BY domain_schema, domain_name;	Drop the default that is associated with the domain.

SQL query

Description

SELECT format('ALTER %4$s TABLE %1$I.%2$I ALTER COLUMN %3$I DROP DEFAULT;', A.table_schema, A.table_name, A.column_name, 
CASE WHEN B.table_type='FOREIGN' THEN table_type END) AS statements
FROM information_schema.columns A INNER JOIN information_schema.schemata S ON A.table_schema=S.schema_name
INNER JOIN information_schema.tables B USING (table_schema, table_name)
WHERE A.column_default~'^NULL::'
AND (A.table_schema = 'public'
OR S.schema_owner<>'postgres')
ORDER BY A.table_schema, A.table_name, A.column_name;

Drop the default that is directly associated with the column.

SELECT format('ALTER DOMAIN %1$I.%2$I DROP DEFAULT;', D.domain_schema, D.domain_name) AS statements
FROM information_schema.domains D INNER JOIN information_schema.schemata S ON D.domain_schema=S.schema_name
WHERE D.domain_default~'^NULL::'
AND (D.domain_schema = 'public'
OR S.schema_owner<>'postgres')
ORDER BY domain_schema, domain_name;

Drop the default that is associated with the domain.

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
Default value	Queries of this catergory provide information about the use of default values.
Missing data	Queries of this category provide information about missing data (NULLs) in a database.

Category name

Category description

Default value

Queries of this catergory provide information about the use of default values.

Missing data

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