Check out example codes for "view detailed table schema postgresql". It will help you in understanding the concepts better.

Code Example 1

-- All information
SELECT * FROM information_schema.columns
WHERE table_schema = 'some_schema'
AND TABLE_NAME = 'some_table';

-- Or a more simplified version

SELECT
   table_name,
   column_name,
   data_type
FROM
   information_schema.columns
WHERE
   table_name = 'some_table';

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