Query goal: | If something has to be unique, then it must be said to the system so that it could use the information for internal optimizations and enforce the constraint. Find columns that contain Universally Unique Identifiers but are not a part of any simple PRIMARY KEY/UNIQUE constraint and are also not part of a foreign key. |
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: | Declare the PRIMARY KEY or UNIQUE constraint. |
Data source: | INFORMATION_SCHEMA+system catalog |
SQL query: | Click on query to copy it
with simple_keys as (select nspname as target_schema, 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 column_name from pg_constraint o inner join pg_class c on c.oid = o.conrelid inner join pg_namespace n on c.relnamespace=n.oid where o.contype in ('p','u') and cardinality(o.conkey)=1 and n.nspname NOT IN (SELECT schema_name FROM INFORMATION_SCHEMA.schemata WHERE schema_name<>'public' AND schema_owner='postgres' AND schema_name IS NOT NULL)), fk as (select (select nspname from pg_namespace where oid=m.relnamespace) as target_schema, m.relname as target_table, m.oid as target_table_oid, o.conkey AS target_col from pg_constraint o inner join pg_class c on c.oid = o.conrelid inner join pg_class m on m.oid = o.conrelid where o.contype = 'f' and o.conrelid in (select oid from pg_class c where c.relkind = 'r')), fk_unnest as (select target_schema, target_table, target_table_oid, target_col, target_col_num, ordin from fk, unnest(fk. target_col) with ordinality as f(target_col_num, ordin)), fk_with_names as (select target_schema, target_table, a_target.attname as target_col from fk_unnest fk inner join pg_attribute a_target on fk.target_col_num = a_target.attnum and fk.target_table_oid = a_target.attrelid and a_target.attisdropped = false), uuid_columns AS (SELECT table_schema, table_name, column_name FROM INFORMATION_SCHEMA.columns WHERE data_type='uuid' AND (table_schema, table_name) IN (SELECT table_schema, table_name FROM INFORMATION_SCHEMA.tables WHERE table_type='BASE TABLE') AND 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)) SELECT table_schema, table_name, column_name FROM uuid_columns AS uc WHERE NOT EXISTS (SELECT * FROM fk_with_names AS fwn WHERE uc.table_schema=fwn.target_schema AND uc.table_name=fwn.target_table AND uc.column_name=fwn.target_col) AND NOT EXISTS ( SELECT * FROM simple_keys AS sk WHERE uc.table_schema=sk.target_schema AND uc.table_name=sk.target_table AND uc.column_name=sk.column_name) ORDER BY table_schema, table_name; |
SQL query | Description |
---|---|
with simple_keys as (select nspname as target_schema, m.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 column_name from pg_constraint o inner join pg_class c on c.oid = o.conrelid inner join pg_namespace n on c.relnamespace=n.oid inner join pg_class m on m.oid = o.conrelid where o.contype in ('p','u') and o.conrelid in (select oid from pg_class c where c.relkind = 'r') and cardinality(o.conkey)=1 and n.nspname NOT IN (SELECT schema_name FROM INFORMATION_SCHEMA.schemata WHERE schema_name<>'public' AND schema_owner='postgres' AND schema_name IS NOT NULL)), uuid_columns AS (SELECT table_schema, table_name, column_name FROM INFORMATION_SCHEMA.columns WHERE data_type='uuid' AND (table_schema, table_name) IN (SELECT table_schema, table_name FROM INFORMATION_SCHEMA.tables WHERE table_type='BASE TABLE') AND 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)), missing_keys AS (SELECT table_schema, table_name, column_name FROM uuid_columns EXCEPT SELECT target_schema, target_table, column_name FROM simple_keys) SELECT format('ALTER TABLE %1$I.%2$I ADD CONSTRAINT %2$I_pkey PRIMARY KEY (%3$I);', table_schema, table_name, column_name) AS statements FROM missing_keys ORDER BY table_schema, table_name; | Declare the primary key. |
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 . |
Category name | Category description |
---|---|
Data types | Queries of this category provide information about the data types and their usage. |
Uniqueness | Queries of this category provide information about uniqueness constraints (PRIMARY KEY, UNIQUE, EXCLUDE) as well as unique indexes. |
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). |