Referential degree of a schema

Goal	Referential degree of a schema is defined as the number of foreign keys in the database schema.
Notes	The query returns information about all the non-system schemas, even those that do not have foreign key constraints. In the latter case the number would be 0.
Type	Sofware measure (Numeric values (software measures) about the database)
License	MIT (opens in new tab)
Data Source	INFORMATION_SCHEMA only
SQL Query	SELECT s.schema_name AS schema, COUNT(tc.table_schema) AS number_of_foreign_keys FROM information_schema.schemata AS s LEFT JOIN (SELECT table_schema FROM information_schema.table_constraints WHERE constraint_type = 'FOREIGN KEY') AS tc ON s.schema_name=tc.table_schema WHERE schema_name NOT IN (SELECT schema_name FROM INFORMATION_SCHEMA.schemata WHERE schema_name<>'public' AND schema_owner='postgres' AND schema_name IS NOT NULL) GROUP BY s.schema_name ORDER BY COUNT(tc.table_schema) DESC, s.schema_name;

Collections

This query belongs to the following collections:

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 .

Find quick numeric overview of the database

Queries that return numeric values showing mostly the number of different types of database objects in the database

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 .
Find quick numeric overview of the database	Queries that return numeric values showing mostly the number of different types of database objects in the database

Categories

This query is classified under the following categories:

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.

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.