(Postgresql) make table 触发器函数将更改行的 ID 值插入日志 table，用于自定义复制

Question

对于 Postgresql---最终是 Sybase ADS---我有 tables 将使用自制触发器进行复制。触发器有一个函数，它应该记录 INSERT UPDATE DELETE 更改的信息，其中包括 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 tables 来测试双向复制。

如果我对 NAME table 进行插入，例如添加自动 ID 为“1”的 'JOHN'，我是否能够插入该 ID 值甚至可能 'JOHN'进入日志 table？我正在查看 OLD.ID 或 NEW.ID 选项，但我不知道这是否可行。我的 trigger/function 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();

这最终是为了使用触发器进行双向复制。感谢您的任何考虑或指导。我会根据需要进行编辑。

Answer 1

我能够通过在触发器中将 AFTER 更改为 BEFORE 来解决这个问题，我认为一开始这是行不通的，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) make table 触发器函数将更改行的 ID 值插入日志 table，用于自定义复制

(Postgresql) make table trigger function insert ID value of changed row into log table, for custom replication

postgresql

triggers

database-replication

multi-master-replication