Question

我正在尝试在数据库升级方法的预先存在的表中添加新列。我有两种看法：

ALTER TABLE foo ADD new_column INTEGER DEFAULT 0

和

ALTER TABLE foo ADD COLUMN new_column INTEGER DEFAULT 0

有什么区别？

Answer 1

func signUpAction(){ guard let email = Email.text, let password = Password.text else{ print("Something is Happenening") return} print(email) print(password) //adds user under the authentication tab on firebase firebaseAuth.createUser(withEmail: email, password: password) { (user, err) in if err != nil { print(err!) print(email) print(password) return } else{ // As per your question, firebase returns nil here print("user - \(user)") if let userInstance = user { self.createProfile(userInstance) } self.performSegue(withIdentifier: "signUpToMainScene", sender: nil) } }关键字是可选的。没有任何区别。

尝试以下脚本：

COLUMN

结果将是：

CREATE TABLE Test
(
    Col1 INTEGER
);

INSERT INTO Test (Col1) VALUES (1);

ALTER TABLE Test 
ADD Col2 INTEGER NULL;

ALTER TABLE Test 
ADD COLUMN Col3 INTEGER NULL;

SELECT * 
FROM Test

在SQLite中添加ADD和ADD COLUMN？

1 个答案: