Re: identity columns ?
От | Josh Berkus |
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Тема | Re: identity columns ? |
Дата | |
Msg-id | web-1050282@davinci.ethosmedia.com обсуждение исходный текст |
Ответ на | Re: identity columns ? (Harald Lux <info@lux.de>) |
Ответы |
Re: identity columns ?
Re: OID |
Список | pgsql-novice |
Harald, Chris, > > 1. M$ SQL Server has an identity column which generates a > sequential number > > for you, we use this often for unique primary keys. Does postgres > support > > anything like this ? > > select *,oid from your_table NO!!!! This is wrong. DO NOT USE the oid for anything other than system purposes. It is NOT a user-friendly value for several reasons. Chris, the data type you want is SERIAL. Please read the section of the docs on sequences: http://www.postgresql.org/idocs/index.php?sql-createsequence.html ... as the SERIAL datatype simply automates the creation of a sequence. BTW, postgres sequences are both more powerful and more user-friendly than MS SQL Identity columns. I would also strongly suggest buying a beginner's postgresql book, such as "PostgreSQL: Introduction and Concepts" or Wrox Press' PostgreSQL book. -Josh Berkus
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