PostgreSQL:INSERT如果不存在，则返回ID

如果没有IP地址，下面的查询将插入IP地址并返回ID

WITH variables AS (
  SELECT '1.1.1.2'::inet AS ip
)
INSERT INTO globals.ips (ip)
SELECT v.ip
FROM variables AS v
WHERE NOT EXISTS (
    SELECT i.global_ip_id 
    FROM globals.ips AS i 
    WHERE i.ip = v.ip
)
RETURNING global_ip_id

但是，当该值已存在于数据库中时，它不会返回ID

当值已经存在时，如何获取ID

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我正在运行PostgreSQL 12。

我不确定它是否最优雅；但它每次都返回IP的ID。

WITH variables AS (
  SELECT '1.1.1.2'::inet AS ip
), wt0 as (
INSERT INTO globals.ips (ip)
SELECT v.ip
FROM variables AS v
WHERE NOT EXISTS (
    SELECT i.global_ip_id 
    FROM globals.ips AS i 
    WHERE i.ip = v.ip
)
RETURNING global_ip_id
)
SELECT global_ip_id FROM wt0
UNION
SELECT id FROM globals.ips WHERE ip = 'SOMETHING';

我只需要输入一次IP

WITH v AS (
   SELECT '1.1.1.110'::inet AS ip
), i AS (
    INSERT INTO globals.ips (ip)
    SELECT * FROM v
    WHERE NOT EXISTS (
        SELECT i.global_ip_id
        FROM globals.ips AS i
        WHERE i.ip = v.ip
    )
    RETURNING global_ip_id
)
SELECT global_ip_id FROM i
UNION ALL
SELECT global_ip_id FROM globals.ips g
LEFT JOIN v ON g.ip = v.ip
WHERE g.ip = v.ip
LIMIT 1;

如果有人对如何改进这一点有建议，请让我知道

更优雅的解决方案：

INSERT INTO globals.ips (ip) VALUES ('1.1.1.1'::inet)
ON CONFLICT (ip) DO UPDATE SET ip = EXCLUDED.ip
RETURNING global_ip_id AS id;

但是，比原来的要慢一点

---

这需要我放置两次IP，我已经用设置了一次IP值。您尝试了吗？因为在我看来没问题。你能提供样本数据吗？是的，我提供了。它要求我将IP“1.1.1.2”放置两次。只有一个ID序列列和一个INET列。