sql - @是什么! From语句中的均值

我正在尝试确定此代码的功能(Oracle SQL)，尤其是from子句中的符号感叹号。

INSERT INTO "LOCATIONS" "A1"
            ("LOCATION_ID",
             "SEQUENCE",
             "POINT_TYPE")
SELECT "A2"."LOCATION_ID",
       "A2"."SEQUENCE",
       "A2"."LOCATION_TYPE",
       "A2"."POINT_TYPE"
FROM   "LOCATIONS"@! "A2"
WHERE  NOT EXISTS (SELECT 1
                   FROM   "LOCATIONS" "A3"
                   WHERE  "A3"."LOCATION_ID" = "A2"."LOCATION_ID")

最佳答案

这是到执行查询的原始数据库的反向数据库链接。原始查询必须如下所示:

INSERT INTO LOCATIONS@remote_db
            ("LOCATION_ID",
             "SEQUENCE",
             "POINT_TYPE")
SELECT "A2"."LOCATION_ID",
       "A2"."SEQUENCE",
       "A2"."POINT_TYPE"
FROM   "LOCATIONS" A2
WHERE  NOT EXISTS (SELECT 1
                   FROM   LOCATIONS@remote_db A3
                   WHERE  "A3"."LOCATION_ID" = "A2"."LOCATION_ID");

这样，所有远程表都将变为本地，而本地表将通过“@!”变为远程。

关于sql - @是什么! From语句中的均值，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/11671303/