PostgreSQL Metadata retrieval

# To get the oid of tables;

    SELECT oid FROM pg_class WHERE relname='m_menu';

# To get attribute details

    SELECT * FROM pg_attribute WHERE attrelid = 'm_menu'::regclass;

# To get only fields information

    SELECT * FROM pg_attribute WHERE attrelid = 'm_menu'::regclass and attnum>0;     

# To get table list     

    SELECT tablename FROM pg_tables where schemaname='public'  order by tablename;

# To get field information of a table

    SELECT a.attname, b.typname, attnum FROM pg_attribute a
    left outer join pg_type b on b.oid = a.atttypid
    WHERE attrelid = upper('claim_id')::regclass and attnum>0 order by attnum;