创建和插入具有多对多关系的数据

Question

我在 postgresql 中尝试了一对多的关系，但是什么都没有

这里是我的错误尝试

CREATE TABLE person_basic_info (
    id                                    INT           NOT NULL PRIMARY KEY,
    gender                                VARCHAR (50)  NULL,
    first_name                            VARCHAR (150) NULL,
    last_name                             VARCHAR (150) NULL,
    email                                 VARCHAR (50)  NULL,
    political_view_id                     INT           NULL,
    cambridge_analytica_psychographics_id INT           NULL REFERENCES persons_features (id),
    revolution_sympathy                   int           NULL,
    iq_level                              INT           NULL
);

创建人物特征

CREATE TABLE persons_features (
    id               INT            NOT NULL PRIMARY KEY,
    dominate_feature VARCHAR (100) NULL
);


--person_basic_info

insert into person_basic_info(id, gender, first_name, last_name, email, political_view_id, cambridge_analytica_psychographics_id,revolution_sympathy,iq_level) values (1,'Female','Corenda','Garrood','cgarrood0@yellowbook.com',6,2,0,86);
insert into person_basic_info(id,gender, first_name, last_name, email, political_view_id, cambridge_analytica_psychographics_id,revolution_sympathy,iq_level) values (2,'Male','Langston','McMychem','lmcmychem1@theatlantic.com',2,4,0,111);
insert into person_basic_info(id,gender, first_name, last_name, email, political_view_id, cambridge_analytica_psychographics_id,revolution_sympathy,iq_level) values (3,'Female','Robbyn','Imison','rimison2@geocities.com',14,3,1,98);


--persons_features
insert into persons_features (id, dominate_feature) values (1,'Agreeableness');
insert into persons_features (id, dominate_feature) values (2,'Conscientiousness');
insert into persons_features (id, dominate_feature) values (3,'Extraversion');
insert into persons_features (id, dominate_feature) values (4,'Neuroticism');
insert into persons_features (id, dominate_feature) values (5,'Openness');

但是什么都没有。

你能帮帮我吗？

Answer 1

如果您以正确的顺序执行此查询，您将不会收到任何错误。在这种情况下正确的顺序应该是：

创建 TABLE persons_features
创建 TABLE person_basic_info
插入 persons_features
插入 person_basic_info

在这种情况下，这不是多对多关系，除非 person 可以有多个 cambridge_analytica_psychographics_id 的值。如果是这样，您应该创建交集 table 而不是引用 persons_features table.

创建和插入具有多对多关系的数据

Create and insert data with many to many relationaships

sql

postgresql

insert

create-table