How to grab the first sql statement's id as foreign key in 2nd sql statement?RSS

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  Happy Bee

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  How to grab the first sql statement's id as foreign key in 2nd sql statement?

  Sep 10, 2019 09:08 AM|Happy Bee|LINK

  I am using Postgres db for C#.net

  How do I grab the first sql statement autoincrement id (primary key) into the second statement as foreign key?
  

  cmd.CommandText = "INSERT INTO table1(a1,a2,a3)VALUES(@a1, @a2,@a3)";
  cmd.CommandText = "INSERT INTO table2 (fk_id, b1)VALUES(@fk_id,@b1)";
  

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  samwu

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  Re: How to grab the first sql statement's id as foreign key in 2nd sql statement?

  Sep 11, 2019 06:36 AM|samwu|LINK

  Hi Happy Bee,

  Happy Bee

  I am using Postgres db for C#.net

  I'm sorry I'm not familiar with Postgres db. 

  But through my search, you can refer to this link to get primary key : https://stackoverflow.com/a/20537829

  then set the foreign key by this link: https://www.postgresql.org/docs/9.2/ddl-constraints.html

  If you can't solve the problem，i suggest you post the question in the Postgres forums.

  Best regards,

  Sam

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  PatriceSc

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  Re: How to grab the first sql statement's id as foreign key in 2nd sql statement?

  Sep 11, 2019 07:40 AM|PatriceSc|LINK

  Hi,

  Don't know much about it but from the doc it is actually a sequence behind the scene and so you should be able to use https://www.postgresql.org/docs/current/functions-sequence.html (maybe nextval() once the insert is done) to retrieve the next value.

  If you have no other answer a specialized forum for PostgreSQL could be better.