我了解PRAGMA foreign_key
和ON DELETE RESTRICT/NO ACTION
的概念,但是我面临的是另一种情况。
我需要删除一个父行,但保持与之关联的子行。例如:
CREATE TABLE A(id, name);
INSERT INTO A(id, name) VALUES (1, "Loreum");
CREATE TABLE B(id, id_A, name) FOREIGN KEY(id_A) REFERENCES A(id);
INSERT INTO B(id, id_A, name) VALUES (1, 1, "Opium");
DELETE FROM A WHERE id = 1;
我想在保持子行完整的同时实现这一目标。这有可能吗?
编辑
上面的示例将我的问题与this question分开。示例可能对某些人有所帮助,他们只有在有代码时才能理解。
最佳答案
您可以使用deferred foreign key constraint进行此操作:
PRAGMA foreign_keys = on;
CREATE TABLE A(id PRIMARY KEY, name);
INSERT INTO A(id, name) VALUES (1, "Loreum");
CREATE TABLE B(id, id_A, name, FOREIGN KEY(id_A) REFERENCES A(id) DEFERRABLE INITIALLY DEFERRED);
INSERT INTO B(id, id_A, name) VALUES (1, 1, "Opium");
BEGIN;
DELETE FROM A WHERE id = 1;
INSERT INTO A(id, name) VALUES (1, "another Loreum");
COMMIT;
关于sqlite - SQLite-如何在保留子行的同时删除父行?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/29349122/