“Fremdschlüssel SQL” Code-Antworten

SQL Fremdschlüssel

create table Jobs(
job_id number not null,
job_title varchar(30),
min_salary number,
max_salary number
);
create table job_history(
employee_id number not null,
start_date date,
end_date date,
job_id number not null,
department_id number
);
alter table jobs add constraint pk_jobs primary key(job_id);
alter table job_history add constraint fk_job foreign key(job_id) references jobs(job_id);
Fierce Ferret

SQL Fremd Schlüsselbeschränkungen

CREATE TABLE Orders (
  order_id INT PRIMARY KEY,
  customer_id int REFERENCES Customers(id)
);
SAMER SAEID

Fremdschlüssel in SQL DBMS

FOREIGN KEY (fk_col_name) 
REFERENCES target_table_name (pk_col_name);
mahmud

Fremdschlüssel SQL

 A foreign key is an attribute of a relation (subordinate/dependent)
that points to the primary key of another relation (main/master)
FK is used to create a many-to-one (one-to-many) relationship.
coder

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