The choice of data types should reveal as much as possible about the nature of the data in the column. The type of these columns could be CHAR(1) and they should have a constraint that a value in the column cannot be an empty string.
Notes
Query returns also information about columns that properties have been specified through a domain.
Type
Problem detection (Each row in the result could represent a flaw in the design)
Change the type of the column and add the constraint.
Data Source
INFORMATION_SCHEMA only
SQL Query
SELECT table_schema, table_name, column_name
FROM INFORMATION_SCHEMA.columns
WHERE (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) AND data_type = 'character varying' AND
character_maximum_length=1
ORDER BY table_schema, table_name, ordinal_position;
Collections
This query belongs to the following collections:
Name
Description
Find problems about base tables
A selection of queries that return information about the data types, field sizes, default values as well as general structure of base tables. 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 .
Categories
This query is classified under the following categories:
Name
Description
Data types
Queries of this category provide information about the data types and their usage.