Question

对于Postgresql（最终是Sybase ADS），我有一些使用自制触发器进行复制的表。触发器具有应记录有关INSERT UPDATE DELETE更改的信息的功能，该更改包括I / U / D操作和更改的行的ID。我正在使用带有名字列和自动递增ID的测试表来测试双向复制。

如果我在NAME表中进行插入（例如添加自动ID为“ 1”的“ JOHN”），我是否可以将该ID值甚至“ JOHN”插入日志表中？我正在查看OLD.ID或NEW.ID选项，但不知道那是如何工作的。我的触发器/功能代码是：

    CREATE OR REPLACE FUNCTION Insert() RETURNS TRIGGER AS $ReplInsert$
    BEGIN
        IF (TG_OP = 'DELETE') THEN
            INSERT INTO "log" ("Operation","ID","NAME")
    VALUES ('DELETE', OLD.ID, OLD.NAME);
            RETURN OLD;
        ELSIF (TG_OP = 'UPDATE') THEN
            INSERT INTO "log" ("Operation","ID","NAME")
    VALUES ('UPDATE', NEW.ID ,NEW.NAME);
            RETURN NEW;
        ELSIF (TG_OP = 'INSERT') THEN
            INSERT INTO "log" ("Operation","ID","NAME")
    VALUES ('UPDATE', NEW.ID , NEW.NAME);
            RETURN NEW;
        END IF;
        RETURN NULL; 
    END;
$ReplInsert$ LANGUAGE plpgsql;

CREATE TRIGGER logTrg
AFTER INSERT OR UPDATE OR DELETE ON "FIRST_NAME"
    FOR EACH ROW EXECUTE PROCEDURE Insert();

这最终将使用触发器进行双向复制。感谢您的任何考虑或指导。我将根据需要进行编辑。

Answer 1

我能够通过将触发器中的AFTER更改为BEFORE来解决此问题，我一开始认为这是行不通的，或者：

    CREATE OR REPLACE FUNCTION Insert() RETURNS TRIGGER AS $ReplInsert$
    BEGIN
        IF (TG_OP = 'DELETE') THEN
            INSERT INTO "log" ("Operation","ID","NAME")
    VALUES ('DELETE', OLD.ID, OLD.NAME);
            RETURN OLD;
        ELSIF (TG_OP = 'UPDATE') THEN
            INSERT INTO "log" ("Operation","ID","NAME")
    VALUES ('UPDATE', NEW.ID ,NEW.NAME);
            RETURN NEW;
        ELSIF (TG_OP = 'INSERT') THEN
            INSERT INTO "log" ("Operation","ID","NAME")
    VALUES ('UPDATE', NEW.ID , NEW.NAME);
            RETURN NEW;
        END IF;
        RETURN NULL; 
    END;
$ReplInsert$ LANGUAGE plpgsql;

CREATE TRIGGER logTrg
BEFORE INSERT OR UPDATE OR DELETE ON "FIRST_NAME"
    FOR EACH ROW EXECUTE PROCEDURE Insert();

（PostgreSQL）使表格触发功能将更改的行的ID值插入日志表中，以进行自定义复制

1 个答案: