Finding columns that are NOT NULL in PostgreSQL
No.
This query
SELECT DISTINCT column_name, table_nameFROM INFORMATION_SCHEMA.COLUMNSWHERE column_name IS NOT NULLwill return all the rows that have a value in the column "column_name".
All rows in that table will always have a value in the column "column_name".
Do you just need to know how many columns are nullable and how many are non-nullable?
SELECT is_nullable, COUNT(*)FROM INFORMATION_SCHEMA.COLUMNSGROUP BY is_nullable;Count by table name? I think you can use this.
SELECT table_name, is_nullable, count(*)FROM INFORMATION_SCHEMA.COLUMNSGROUP BY table_name, is_nullableORDER BY table_name, is_nullable;
To get a count of all NOT NULL columns in any table, use:
SELECT count(*) FROM information_schema.columns WHERE table_schema = 'table_schema_here' AND table_name = 'table_name_here' AND is_nullable = 'YES';I hope this will help someone.
To get a count of all NOT NULL columns:
SELECT count(*) FROM information_schema.columns WHERE table_name = 'table_name' AND is_nullable = 'NO';