SQLite FOREIGN KEY ON DELETE CASCADE无效

时间:2017-06-29 09:35:32

标签: sqlite cascade

我在SQLite版本3.16.0上运行以下脚本wtf.sql

PRAGMA foreign_keys = ON;

CREATE TABLE 'ZIP'(
  'Zip' INTEGER PRIMARY KEY NOT NULL,
  'City' TEXT NOT NULL,
  'State' TEXT NOT NULL
);
CREATE TABLE 'ADDRESS'(
  'Address_id' INTEGER PRIMARY KEY AUTOINCREMENT,
  'Line_1' TEXT NOT NULL,
  'Line_2' TEXT,
  'Zip' INTEGER NOT NULL,
  FOREIGN KEY('Zip') REFERENCES ZIP('Zip') ON DELETE CASCADE
);

INSERT OR IGNORE INTO ZIP('Zip','City','State')
  VALUES ('90210','Beverly Hills','CA')
;
INSERT INTO ADDRESS('Line_1','Line_2','Zip')
  VALUES ('1234 Overpriced House Street','c/o Bob','90210')
;
DELETE FROM ADDRESS
  WHERE Zip = '90210'
;
SELECT *
  FROM ZIP
;

将以下内容键入bash:

$ sqlite3 bits-n-books.db < wtf.sql

返回以下元组:

90210|Beverly Hills|CA

如果要正确删除级联,我需要做什么?

1 个答案:

答案 0 :(得分:2)

INSERT INTO ADDRESS(Line_1,Line_2,Zip)
  VALUES ('1234 Overpriced House Street','c/o Bob','90210'),
         ('667 Another Street','2nd row','90210');

DELETE FROM ADDRESS WHERE Line_2 = '2nd row';

现在应该怎么办?是否还应删除引用90210的所有其他地址?

删除父行时,ON DELETE CASCADE action会删除所有子行。在这种情况下,这意味着从ZIP删除行将删除所有相应的ADDRESS行。另一方面没有类似的机制。