Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1l7K0M-00025r-DV for pgsql-admin@arkaria.postgresql.org; Wed, 03 Feb 2021 15:23:42 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.92) (envelope-from ) id 1l7K0K-0000M3-DV for pgsql-admin@arkaria.postgresql.org; Wed, 03 Feb 2021 15:23:40 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1l7K0K-0000Lw-1o for pgsql-admin@lists.postgresql.org; Wed, 03 Feb 2021 15:23:40 +0000 Received: from mail-wr1-x429.google.com ([2a00:1450:4864:20::429]) by magus.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1l7K0H-00056Z-B0 for pgsql-admin@lists.postgresql.org; Wed, 03 Feb 2021 15:23:39 +0000 Received: by mail-wr1-x429.google.com with SMTP id q7so24785045wre.13 for ; Wed, 03 Feb 2021 07:23:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=webedia-group-com.20150623.gappssmtp.com; s=20150623; h=from:content-transfer-encoding:mime-version:subject:message-id:date :to; bh=u9pE1rJk1l3Jx0rrPTKjMB6QlQBd3MxHqO18KaqjwNY=; b=vPf54mP9akjCdf6+7uzChTl48m1OOqsrWGJYY5aERtWwUyXhwUK+D3idB/GZNUqPKI IEJ96FlYw8DYonNyCa6ROJLZl30XGrGODZXwmV2l1aPj8MDjnCafuy72gcOcUG2FzybC 88XmvsGY4+oO4k6XPmnhKNu74JP5hkoA/b2IkCljVaYx82PtR6x3qY8L95RdI2H+vW8k dn4WxVt+jwzYxoVgsWjPITB0X9UCxN+YnbcgJDwYIvP2DyVUyIYSocT84UVXEtcZHNsc DPa4LDWmirCjID6DT0rq6V5cBWzRFpbmT1rgjRzoQbB9fgOgztmcihgMiI3Nb6rgPA0i CV2A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:content-transfer-encoding:mime-version :subject:message-id:date:to; bh=u9pE1rJk1l3Jx0rrPTKjMB6QlQBd3MxHqO18KaqjwNY=; b=X5oWbhX6CjNwIXML921eJO/E5tk2rI726nUjJY8BmUk0w6+8L+DGcQu2dBCDhvxIFm 0z/Jv8AnMlgFThW697uDieo30slwOpQGn+owaAo7st+Hmfpfpb1k9aSA8DzxtbmtW068 P9SUxwfRO0pt6S32UQvkflRzrPksQOpY+nn4lMIEfZqkWJPOFDSKOQbSzYD7l32DLHtY 7Y+aX0XwMCvsZSv5O+xueqdz/lwFyQLZxnfkodRB/ZRFq8e6gKb33mJH/2g/5wCgil56 ymzwp5ZWIDGIaCKPpgaj/JwQmC5Tcbmh1iSLSA2VKVe5w84Ag+u2eaHdHdsJGI2YJ2GL Zy7w== X-Gm-Message-State: AOAM531vwLlXk3ZBRM62kfplpaF+lnvXrF+JioKYyzvfgqBBSOoP/cBi AyU6syCaxrcz6Qz4bn1lLIUD6PkLAPR+YdckkCXM4HonuZwECadnZuGD7dg2pgbyvROWEdRdijj 50Hv0Z6Ui50LVSdKX2Xo0LqPTz3YCmol01zdKAWqh5gQlUnjDAm/JyfZ/4RIf0F428blsKzdIz2 3JVoUhNMJmFuIMn4P+VJPzSg== X-Google-Smtp-Source: ABdhPJxm+K+QtLN/fXhIR/3WLf/Zd5INKhGUEmbHGRsrG58Ab9Rhc4zpfq3J1N4BpQjVqclZ1DlAoQ== X-Received: by 2002:adf:ecc5:: with SMTP id s5mr3999159wro.423.1612365815031; Wed, 03 Feb 2021 07:23:35 -0800 (PST) Received: from [192.168.0.22] (91-170-201-226.subs.proxad.net. [91.170.201.226]) by smtp.gmail.com with ESMTPSA id z14sm4111389wrm.5.2021.02.03.07.23.33 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 03 Feb 2021 07:23:34 -0800 (PST) From: Mai Peng Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.40.0.2.32\)) Subject: Design database Message-Id: Date: Wed, 3 Feb 2021 16:23:33 +0100 To: pgsql-admin@lists.postgresql.org X-Mailer: Apple Mail (2.3654.40.0.2.32) List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk Hello, I=E2=80=99ve got a table name publication, and another table named = publication_item.=20 Each publication_item is linked to a publication by publication_id. How could I add a constraint that check each publication has one or more = publication_item when a tuple is inserted ? I don=E2=80=99t want to store items in the same table as publication = because we could have 1-> n items. Thank you