在SQLite中实现/使用外键？ [英] Implement/use foreign keys in SQLite?

问题描述

我怎样才能在SQLite中实现一个外键？我在想这样的事情：
$ b $ pre $ CREATE TABLE雇主（_id INTEGER，employer_name TEXT NOT NULL，...）;


其中 employer_id 是 _id 来自表雇主。这会工作吗？有没有另一种快速，也许不太容易出错的方式？也许与触发器？可能我不明白的问题，但如果这是你想要的约束，只要这样做：

pre $ ALTER TABLE作业
添加FOREIGN KEY（employer_id）
REFERENCES雇主（_id）
ON DELETE NO ACTION
ON UPDATE NO ACTION;


How can I implement a foreign key in SQLite? I was thinking something like this:

CREATE TABLE job (_id INTEGER PRIMARY KEY AUTOINCREMENT, employer_id INTEGER, ...);
CREATE TABLE employer(_id INTEGER, employer_name TEXT NOT NULL, ...);

Where employer_id is the _id from the table employer. Would this work? Is there another fast, maybe less prone to error way? Maybe with triggers?

解决方案

Maybe I don't understand the question, but if it's the constraint you want, just do this:

ALTER TABLE Job
  ADD FOREIGN KEY (employer_id)
    REFERENCES Employer(_id)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION;

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