The expression of a check constraint that is associated with a domain needs type conversion

Query goal:

Find check constraints of domains where the Boolean expression invokes an operation that does not match with the data type of the domain.

Query type:

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

Query reliability:

Medium (Medium number of false-positive results)

Query license:

MIT License

Fixing suggestion:

Perhaps the Boolean expression is incorrect. For instance, in case of price domain CHECK(VALUE::text<>''). In this case drop the constraint and think through what you have to check, whether the check is implemented already with the selection of data type, and if not then what would be a correct Boolean expression. It could also be that the data type of the domain is incorrect and has to be changed.

Data source:

INFORMATION_SCHEMA only

SQL query:

Click on query to copy it

WITH checks AS (SELECT dc.domain_schema, dc.domain_name, d.data_type, cc.constraint_name, cc.check_clause
FROM INFORMATION_SCHEMA.domain_constraints AS dc
INNER JOIN INFORMATION_SCHEMA.domains AS d USING (domain_schema, domain_name)
INNER JOIN INFORMATION_SCHEMA.check_constraints AS cc USING (constraint_schema, constraint_name)
WHERE cc.check_clause NOT LIKE '%IS NOT NULL'  AND 
dc.domain_schema NOT IN (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL))
SELECT domain_schema, domain_name, data_type, constraint_name, check_clause 
FROM checks
WHERE (data_type !~* '^(character|text)' AND check_clause ~*'::(bpchar|character|text).*(=|>|<|~).*::(bpchar|character|text)' AND check_clause !~*'(to_date|to_timestamp)[(][^)]*::(bpchar|character|text)')
OR
(data_type ~* '^(character|text)' AND check_clause !~*'::(bpchar|character|text)' AND check_clause ~*'::')
ORDER BY domain_schema, domain_name;

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

SQL query	Description
WITH checks AS (SELECT dc.domain_schema, dc.domain_name, d.data_type, cc.constraint_name, cc.check_clause FROM INFORMATION_SCHEMA.domain_constraints AS dc INNER JOIN INFORMATION_SCHEMA.domains AS d USING (domain_schema, domain_name) INNER JOIN INFORMATION_SCHEMA.check_constraints AS cc USING (constraint_schema, constraint_name) WHERE cc.check_clause NOT LIKE '%IS NOT NULL' AND dc.domain_schema NOT IN (SELECT schema_name FROM INFORMATION_SCHEMA.schemata WHERE schema_name<>'public' AND schema_owner='postgres' AND schema_name IS NOT NULL)) SELECT format('ALTER TABLE %1$I.%2$I DROP CONSTRAINT %3$I;', domain_schema, domain_name, constraint_name) AS statements FROM checks WHERE (data_type !~* '^(character\|text)' AND check_clause ~'::(bpchar\|character\|text).(=\|>\|<\|~).::(bpchar\|character\|text)' AND check_clause !~'(to_date\|to_timestamp)[(][^)]::(bpchar\|character\|text)') OR (data_type ~ '^(character\|text)' AND check_clause !~'::(bpchar\|character\|text)' AND check_clause ~'::') ORDER BY domain_schema, domain_name;	Drop the constraint.

SQL query

Description

WITH checks AS (SELECT dc.domain_schema, dc.domain_name, d.data_type, cc.constraint_name, cc.check_clause
FROM INFORMATION_SCHEMA.domain_constraints AS dc
INNER JOIN INFORMATION_SCHEMA.domains AS d USING (domain_schema, domain_name)
INNER JOIN INFORMATION_SCHEMA.check_constraints AS cc USING (constraint_schema, constraint_name)
WHERE cc.check_clause NOT LIKE '%IS NOT NULL'  AND 
dc.domain_schema NOT IN (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL))
SELECT format('ALTER TABLE %1$I.%2$I DROP CONSTRAINT %3$I;', domain_schema, domain_name, constraint_name) AS statements
FROM checks
WHERE (data_type !~* '^(character|text)' AND check_clause ~*'::(bpchar|character|text).*(=|>|<|~).*::(bpchar|character|text)' AND check_clause !~*'(to_date|to_timestamp)[(][^)]*::(bpchar|character|text)')
OR
(data_type ~* '^(character|text)' AND check_clause !~*'::(bpchar|character|text)' AND check_clause ~*'::')
ORDER BY domain_schema, domain_name;

Drop the 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
CHECK constraints	Queries of this category provide information about CHECK constraints.
Data types	Queries of this category provide information about the data types and their usage.
Domains	Queries of this category provide information about reusable specifications of column properties.
Validity and completeness	Queries of this category provide information about whether database design represents the world (domain) correctly (validity) and whether database design captures all the information about the world (domain) that is correct and relevant (completeness).

Category name

Category description

CHECK constraints

Queries of this category provide information about CHECK constraints.

Data types

Queries of this category provide information about the data types and their usage.

Domains

Queries of this category provide information about reusable specifications of column properties.

Validity and completeness

Queries of this category provide information about whether database design represents the world (domain) correctly (validity) and whether database design captures all the information about the world (domain) that is correct and relevant (completeness).