错误：关系“student_id_seq”不存在SQL状态：42P01

Question

-- Table: public.student

-- DROP TABLE public.student;

CREATE TABLE public.student
(

   id integer NOT NULL DEFAULT nextval('student_id_seq'::regclass),
   country character varying(30) COLLATE pg_catalog."default" NOT NULL,
   email character varying(30) COLLATE pg_catalog."default" NOT NULL,
   first_name character varying(255) COLLATE pg_catalog."default" NOT NULL,
   last_name character varying(255) COLLATE pg_catalog."default" NOT NULL,
   section character varying(255) COLLATE pg_catalog."default" NOT NULL,
   sex character varying(255) COLLATE pg_catalog."default" NOT NULL,
   CONSTRAINT student_pkey PRIMARY KEY (id)
)
WITH (
  OIDS = FALSE
) 
TABLESPACE pg_default;

ALTER TABLE public.student
OWNER to postgres;

我的查询不执行

错误：关系“student_id_seq”不存在SQL状态：42P01

Answer 1

在查询id integer NOT NULL中，默认nextval('student_id_seq'::RegClass)这意味着您希望您的表获得下一个值，该值存储在序列student_id_seq中，用于列id的默认值。

试试看：

CREATE TABLE public.student (
id serial not null,
country character varying(30) COLLATE pg_catalog."default" NOT NULL,
email character varying(30) COLLATE pg_catalog."default" NOT NULL,
first_name character varying(255) COLLATE pg_catalog."default" NOT NULL,
last_name character varying(255) COLLATE pg_catalog."default" NOT NULL,
section character varying(255) COLLATE pg_catalog."default" NOT NULL,
sex character varying(255) COLLATE pg_catalog."default" NOT NULL,
CONSTRAINT student_pkey PRIMARY KEY (id)
) WITH ( OIDS = FALSE ) TABLESPACE pg_default;

ALTER TABLE public.student OWNER to postgres;

通过将串行伪类型分配给id列，PostgreSQL将执行以下操作：

null