如何将唯一更新的行移动到 hist_table postgres？

Question

我创建了下一个触发器，以便在更新或插入时将数据从主表移动到历史表。

CREATE OR REPLACE FUNCTION process_employee_hist() RETURNS TRIGGER AS $employee_hist$
    BEGIN
        IF (TG_OP = 'UPDATE') THEN
            INSERT INTO employee_hist SELECT 'U', now(), user, NEW.*;
            RETURN NEW;
        ELSIF (TG_OP = 'INSERT') THEN
            INSERT INTO employee_hist SELECT 'I', now(), user, NEW.*;
            RETURN NEW;
        END IF;
        RETURN NULL;
    END;
$employee_hist$ LANGUAGE plpgsql;

CREATE TRIGGER employee_hist
AFTER INSERT OR UPDATE ON employee
    FOR EACH ROW EXECUTE PROCEDURE process_employee_hist();

此触发器将所有数据从主表移动到历史记录。 我只需要将更新的移动到历史表中。

Answer 1

尝试：

CREATE OR REPLACE FUNCTION process_employee_hist() RETURNS TRIGGER AS $employee_hist$
BEGIN
    IF (TG_OP = 'UPDATE') THEN
        INSERT INTO employee_hist SELECT 'U', now(), user, NEW.*;
        RETURN NEW;
    END IF;
    RETURN NULL;
END;
$employee_hist$ LANGUAGE plpgsql;

CREATE TRIGGER employee_hist
AFTER UPDATE ON employee
    FOR EACH ROW EXECUTE PROCEDURE process_employee_hist();