| Query goal: | Find base tables where all the columns are optional, i.e., permit NULLs. In such tables can be rows with no identity value and thus indistinguishable from other rows. |
| 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: | Find columns that must be mandatory and declare to these NOT NULL constraint. Declare the primary key because primary key columns are automatically mandatory. |
| Data source: | INFORMATION_SCHEMA only |
| SQL query: | Click on query to copy it
SELECT table_schema, table_name FROM information_schema.columns AS c 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 table_type='BASE TABLE' GROUP BY table_schema, table_name HAVING Count(*) = Count(*) FILTER (WHERE is_nullable='YES') ORDER BY table_schema, table_name; |
| Collection name | Collection 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 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 . |
| Category name | Category description |
|---|---|
| Missing data | Queries of this category provide information about missing data (NULLs) in a database. |
| 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). |