oracle - ORA-02287 : sequence number not allowed here

Question

我试图从两个表中选择值并将它们插入到一个表中并计算每年的总展示次数。我一直收到一个错误，说这里不允许使用序列

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);

Answer 1

您可以在 FAQ 中找到原因

The following are the cases where you can't use a sequence:

For a SELECT Statement:

• In a WHERE clause
• In a GROUP BY or ORDER BY clause
• In a DISTINCT clause
• Along with a UNION or INTERSECT or MINUS
• In a sub-query