小编fre*_*999的帖子

我试图从两个表中选择值并将它们插入一个表中,并计算每年总计的展示位置数.我一直收到一个错误,说这里不允许序列

DROP table placement_cal CASCADE CONSTRAINTS;

CREATE TABLE placement_cal(
    cal_id  INTEGER NOT NULL,
    year    INTEGER,
    no_of_placements INTEGER,
    CONSTRAINT  pk_cal_dim PRIMARY KEY (cal_id)
);


INSERT INTO placement_cal (
SELECT cal_id.nextval  , EXTRACT(YEAR FROM start_date) , count(placement_id)
FROM placement
group by year);

INSERT INTO placement_cal (
SELECT cal_id.nextval  , EXTRACT(YEAR FROM start_date) , count(placement_id)
FROM placement_two
group by year);